Healthy Veggie Breakfast Casserole with Spinach and Eggs

Name: Healthy Veggie Breakfast Casserole with Spinach and Eggs
Prep time: 15 min
Cook time: 40 min
Total time: 55 min
Yield: 6 servings
Cuisine: American
Ingredients: 2 teaspoons olive oil (for sauteing the vegetables); 1 medium courgette (diced into small cubes, about 1.5 cups); 200 grams chestnut mushrooms (roughly chopped); 1 medium red bell pepper (deseeded and diced); 4 spring onions (finely sliced, green and white parts); 2 cloves garlic (minced); 100 grams baby spinach (fresh, roughly chopped); 6 large whole eggs (free-range if possible); 4 large egg whites (helps boost protein without adding fat); 60 millilitres semi-skimmed milk (or unsweetened oat milk for dairy-free); 0.5 teaspoon ground turmeric (adds colour and anti-inflammatory properties); 0.5 teaspoon smoked paprika; 0.25 teaspoon black pepper (freshly ground); 0.5 teaspoon fine sea salt; 80 grams light feta cheese (crumbled, use reduced-fat variety); 3 tablespoons fresh flat-leaf parsley (roughly chopped); 1 tablespoon fresh chives (finely snipped, optional); 1 spray olive oil cooking spray (for greasing the dish)

High ProteinKetoGluten-FreeMeal PrepNut-Free

Prep Time15 min

Cook Time40 min

Servings6

Calories210 kcal

Health Score7/10

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Some mornings call for something warm, filling and genuinely good for you. This healthy veggie breakfast casserole with spinach and eggs delivers all three, and then some. It brings together baby spinach, roasted red peppers, courgette, mushrooms and spring onions in a savoury egg base that bakes up golden and fluffy. A light scatter of crumbled feta adds just enough creaminess without piling on unnecessary fat or calories. Every slice gives you a real hit of protein and fibre to keep you full and focused all morning long.

What makes this casserole stand out from traditional versions is the balance it strikes. Most classic breakfast bakes lean heavily on starchy bread layers, full-fat cheese and processed meats. This one flips that script. Swapping those dense fillers for nutrient-dense vegetables means you get more vitamins, more fibre and far fewer empty calories per serving. The eggs provide a complete protein source, and using a mix of whole eggs with a few extra egg whites bumps the protein content even higher without making the texture rubbery. A little ground turmeric stirred into the egg mixture adds a warm golden colour and brings its own quiet anti-inflammatory benefits to the table.

The beauty of this recipe is how flexible it is. You can prep the whole thing the night before and simply slide it into the oven when you wake up. It feeds six comfortably, making it brilliant for family breakfasts, weekend hosting or a week of make-ahead meal prep. Slice it into portions once cooled, store them in the fridge and you have a grab-and-reheat breakfast ready for busy mornings. The flavours actually deepen overnight, so Tuesday's slice might taste even better than Sunday's. Fresh herbs like flat-leaf parsley or chives stirred through the mixture just before baking bring a brightness that lifts the whole dish.

Nutrition-wise, each serving clocks in at around 210 calories with over 18 grams of protein, under 7 grams of carbohydrates and a solid 2.5 grams of fibre. That makes it genuinely suitable for low-carb and keto-friendly eating patterns, and it is naturally gluten free. If you are feeding people with different dietary needs, this casserole is the kind of crowd-pleaser that quietly works for almost everyone. Serve it with a simple green salad or a piece of wholegrain toast on the side if you want to round it out further. Either way, it is a breakfast that earns its place on any table.

Ingredients

Serves:6

2 teaspoons olive oil (for sauteing the vegetables)
1 medium courgette (diced into small cubes, about 1.5 cups)
200 grams chestnut mushrooms (roughly chopped)
1 medium red bell pepper (deseeded and diced)
4 spring onions (finely sliced, green and white parts)
2 cloves garlic (minced)
100 grams baby spinach (fresh, roughly chopped)
6 large whole eggs (free-range if possible)
4 large egg whites (helps boost protein without adding fat)
60 millilitres semi-skimmed milk (or unsweetened oat milk for dairy-free)
0.5 teaspoon ground turmeric (adds colour and anti-inflammatory properties)
0.5 teaspoon smoked paprika
0.3 teaspoon black pepper (freshly ground)
0.5 teaspoon fine sea salt
80 grams light feta cheese (crumbled, use reduced-fat variety)
3 tablespoons fresh flat-leaf parsley (roughly chopped)
1 tablespoon fresh chives (finely snipped, optional)
1 spray olive oil cooking spray (for greasing the dish)

Instructions

1
Preheat your oven to 190 degrees Celsius (375 degrees Fahrenheit) and lightly spray a 9x13 inch baking dish with olive oil cooking spray. Set it aside.
A ceramic or glass baking dish works best here for even heat distribution.
2
Heat the olive oil in a large non-stick frying pan over a medium heat. Add the diced courgette, red pepper and mushrooms. Cook for 5 to 6 minutes, stirring occasionally, until the vegetables have softened and any excess moisture from the mushrooms has evaporated.
Do not skip this step. Cooking off the moisture from the vegetables prevents a watery casserole.
3
Add the minced garlic and spring onions to the pan. Cook for another minute until fragrant. Stir in the baby spinach a handful at a time, letting each addition wilt before adding the next. This should take about 2 minutes. Remove the pan from the heat and let the mixture cool slightly.
4
In a large mixing bowl, whisk together the whole eggs, egg whites and milk until fully combined and slightly frothy. Add the turmeric, smoked paprika, salt and black pepper and whisk again to incorporate the spices evenly throughout the mixture.
Whisking the eggs well adds air and helps the casserole bake up light and fluffy rather than dense.
5
Spread the cooked vegetable mixture evenly across the bottom of the prepared baking dish. Pour the egg mixture over the top, gently pressing down on the vegetables with a spatula so everything is submerged and evenly distributed.
6
Scatter the crumbled feta evenly over the surface. Sprinkle the chopped parsley and chives across the top.
Pushing a few pieces of feta gently below the surface as well as leaving some on top gives you pockets of creaminess throughout.
7
Bake in the preheated oven for 28 to 32 minutes, until the egg is fully set in the centre and the top is lightly golden. To check doneness, insert a knife into the middle. It should come out clean with no liquid egg.
If the top is browning too quickly before the centre is set, loosely cover the dish with foil for the last 10 minutes.
8
Remove from the oven and allow the casserole to rest for 5 minutes before slicing. This resting time lets the egg firm up further, making for much neater slices.
9
Slice into 6 equal portions and serve warm. Add a pinch of extra chilli flakes or a drizzle of hot sauce at the table if you like a little heat.

Nutrition per serving

210kcal

Calories

18.5g

Protein

6.8g

Carbs

12.2g

Fat

2.5g

Fibre

3.4g

Sugar

420mg

Sodium

Pro Tips

✓
Squeeze out any excess moisture from the courgette with a clean kitchen towel if it seems particularly watery before sauteing.
✓
Let the sauteed vegetable mixture cool for at least 5 minutes before adding the egg mixture. Adding raw egg to very hot vegetables can start scrambling the eggs prematurely.
✓
For a deeper flavour, roast the red pepper in the oven at 200C for 15 minutes before dicing and adding it to the pan.
✓
Using a mix of whole eggs and egg whites is the key to hitting higher protein numbers without pushing the fat content up. The ratio here keeps the texture rich but not heavy.
✓
Season generously. Eggs need a proper amount of salt to taste their best, and vegetables can absorb seasoning quickly.

Frequently Asked Questions

Can I make this healthy veggie breakfast casserole the night before?↓

Absolutely. You can assemble the entire casserole, cover the dish tightly with cling film and refrigerate it overnight. In the morning, pull it from the fridge while the oven preheats, then bake as directed. You may need to add 3 to 5 extra minutes to the bake time since the dish will be cold.

How long does the casserole keep in the fridge?↓

Stored in an airtight container, slices will keep well in the fridge for up to 4 days. Reheat individual portions in the microwave for 60 to 90 seconds, or warm in a low oven for 10 minutes.

Can I freeze this egg and spinach casserole?↓

Yes, it freezes well. Let the casserole cool completely, slice it into individual portions, wrap each one tightly in cling film and place them in a freezer bag. They will keep for up to 2 months. Defrost overnight in the fridge and reheat thoroughly before eating.

Is this casserole gluten free?↓

Yes, the recipe as written contains no gluten. All the ingredients are naturally gluten free. Just double-check that your feta and any spices you use are not processed in facilities that handle gluten if you have a severe intolerance or coeliac disease.

What other vegetables can I add to this casserole?↓

This recipe is very versatile. Diced cherry tomatoes, sliced asparagus, grated sweet potato, frozen peas (thawed and drained), broccoli florets or sliced sun-dried tomatoes all work beautifully. Just ensure any extra vegetables are cooked or patted dry before going into the dish to avoid excess liquid.

Can I make this dairy free?↓

Easily. Swap the semi-skimmed milk for unsweetened oat milk or almond milk, and replace the feta with a dairy-free feta alternative or simply leave the cheese out entirely. Nutritional yeast scattered over the top before baking gives a slightly cheesy, savoury note without any dairy.

Variations

•
Mediterranean Style
Add 50 grams of sliced Kalamata olives and a handful of halved cherry tomatoes to the vegetable mix. Swap the smoked paprika for dried oregano and use crumbled feta generously. Finish with a drizzle of extra virgin olive oil before serving.
•
Spicy Tex-Mex
Add half a tin of drained black beans and a diced jalapeno to the vegetable saute. Season the egg mixture with cumin and chilli powder instead of turmeric and smoked paprika. Top with a spoonful of tomato salsa and sliced avocado when serving.
•
Herby Garden
Double the fresh herbs and add a handful of chopped fresh basil and dill to the egg mixture. Swap the feta for a small amount of crumbled goat cheese. This version has a lighter, more delicate flavour that works beautifully in spring and summer.
•
Protein Boost
Stir 100 grams of cooked, diced turkey sausage or crumbled chicken sausage into the vegetable mixture before adding the eggs. This pushes the protein per serving to over 24 grams and makes the casserole heartier for anyone with higher calorie needs.

Substitutions

•
Baby spinach → Kale or Swiss chard (Remove tough stems and chop finely. Kale needs a slightly longer saute time, around 3 to 4 minutes, to soften fully before going into the baking dish.)
•
Feta cheese → Goat cheese or reduced-fat ricotta (Goat cheese gives a creamier texture, while ricotta dolloped over the top adds a mild richness. Both work well with the vegetable combination in this recipe.)
•
Chestnut mushrooms → Portobello or shiitake mushrooms (Both varieties have a meatier texture and deeper umami flavour. Chop portobello mushrooms into smaller pieces so they cook evenly within the same time frame.)
•
Semi-skimmed milk → Unsweetened almond milk or oat milk (A straight swap at the same quantity. Almond milk keeps the calorie count slightly lower, while oat milk adds a subtle creaminess to the egg mixture.)
•
Courgette → Asparagus tips or diced sweet potato (Asparagus tips can go in raw as they cook quickly. Sweet potato should be parboiled for 5 minutes first or cut into very small cubes and added to the saute pan early so it has time to soften.)
•
Egg whites → Whole eggs (If you prefer not to use separate egg whites, simply use 9 whole eggs in total. The fat content will increase slightly but the recipe remains very nutritious and the texture will be slightly richer.)

🧊 Storage

Allow the casserole to cool to room temperature before storing. Slice into individual portions and store in an airtight container in the refrigerator for up to 4 days. Reheat in the microwave on full power for 60 to 90 seconds, or in a preheated oven at 170C for 8 to 10 minutes. For freezing, wrap individual slices tightly and freeze for up to 2 months. Defrost overnight in the fridge before reheating.

📅 Make Ahead

Assemble the full casserole up to 12 hours ahead. Spread the cooked vegetables in the baking dish, pour over the egg mixture, top with feta and herbs, then cover tightly with cling film and refrigerate. When ready to bake, remove from the fridge while the oven preheats. Bake as directed, adding 3 to 5 extra minutes to account for the colder starting temperature.