High Protein Breakfast Casserole with Chicken and Spinach
Some mornings call for something that actually holds you together until lunch, and this high protein breakfast casserole with chicken and spinach is exactly that. We are talking tender shredded chicken breast, wilted baby spinach, fluffy eggs, creamy cottage cheese, and a generous scatter of crumbled feta all baked into one golden, satisfying dish. It is the kind of breakfast that fuels a genuinely productive morning without leaving you reaching for a mid-morning snack.
What makes this casserole genuinely healthier than most traditional versions starts with the cottage cheese. Blending it smooth before mixing it into the egg base adds a remarkable creaminess while dramatically boosting the protein content without a single extra calorie from heavy cream or full-fat cheese sauces. Paired with lean chicken breast and six whole eggs, each serving clocks in at around 38 grams of protein and well under 350 calories. The baby spinach brings iron, folate, and a gorgeous green colour, while the cherry tomatoes add natural sweetness and lycopene without any added sugar. This is a recipe that works as hard for your nutrition as it does for your taste buds.
The beauty of this dish is its total flexibility for meal prep. You can assemble the entire casserole the night before, cover it tightly, and slide it straight into the oven the next morning. It slices cleanly into eight portions, making it ideal for a week of grab-and-go breakfasts. Reheat a slice in the microwave for 90 seconds and you have a restaurant-quality protein breakfast faster than most people can make toast. The flavour actually deepens overnight as the herbs and garlic infuse through every layer, so do not be put off by the idea of making it ahead.
A few things worth knowing before you start. Make sure you squeeze every last bit of moisture from your thawed frozen spinach if you choose to use it instead of fresh, because excess water can make the centre of the casserole soggy. Fresh baby spinach wilted briefly in a dry pan is the most reliable option and takes only two minutes. Use a 9x13 inch baking dish and make sure it is well greased so the casserole lifts out cleanly. Let it rest for five minutes after pulling it from the oven before slicing. That short rest allows the egg proteins to finish setting, giving you neat, satisfying squares rather than a scrambled mess on the plate.
Ingredients
- 500 g cooked chicken breast (shredded, rotisserie or poached works well)
- 6 large eggs (free-range if possible)
- 400 g low-fat cottage cheese (blended smooth)
- 150 g baby spinach (wilted and any excess water squeezed out)
- 150 g cherry tomatoes (halved)
- 100 g reduced-fat feta cheese (crumbled)
- 1 medium brown onion (finely diced)
- 3 cloves garlic (minced)
- 1 tsp olive oil (for sauteing the onion)
- 1 tsp dried oregano
- 0.5 tsp smoked paprika
- 0.3 tsp ground black pepper
- 0.5 tsp sea salt (adjust to taste)
- 2 tbsp fresh flat-leaf parsley (roughly chopped, for topping)
- 1 tsp olive oil spray (for greasing the baking dish)
Instructions
- 1
Preheat your oven to 190 degrees Celsius (375 Fahrenheit). Lightly grease a 9x13 inch baking dish with olive oil spray and set it aside.
Use a glass or ceramic dish for the most even heat distribution and easy cleanup.
- 2
Heat one teaspoon of olive oil in a small non-stick frying pan over medium heat. Add the diced onion and cook for 4 to 5 minutes, stirring occasionally, until softened and just starting to turn golden. Add the minced garlic and cook for a further 60 seconds. Remove from heat and allow to cool slightly.
Cooling the onion mixture before adding it to the eggs prevents the eggs from beginning to scramble.
- 3
Place your baby spinach in the same pan over medium-low heat with no oil added. Stir for 1 to 2 minutes until wilted. Transfer to a clean tea towel or a few sheets of paper towel and squeeze firmly to remove as much liquid as possible. Roughly chop the wilted spinach.
This step is genuinely important. Excess spinach moisture is the main reason breakfast casseroles end up watery in the centre.
- 4
Add the cottage cheese to a blender or food processor and blend until completely smooth, about 30 seconds. This creates a creamy, custard-like base without any grainy texture.
- 5
In a large mixing bowl, whisk together the six eggs until the yolks and whites are fully combined. Add the blended cottage cheese, oregano, smoked paprika, salt, and black pepper. Whisk again until everything is smooth and uniform.
Taste the egg mixture at this point and adjust seasoning if needed before adding the remaining ingredients.
- 6
Add the shredded chicken, wilted chopped spinach, sauteed onion and garlic, and half of the crumbled feta to the egg mixture. Stir gently with a spatula until everything is evenly distributed.
- 7
Pour the entire mixture into your prepared baking dish and spread it out evenly. Scatter the halved cherry tomatoes across the top, pressing them in very lightly. Sprinkle the remaining feta over everything.
Pressing the tomatoes in slightly ensures they do not roll off and they sink into the egg base as it bakes.
- 8
Bake in the preheated oven for 35 to 40 minutes, until the centre is fully set and the top is lightly golden. To check doneness, insert a clean knife into the centre of the casserole. It should come out clean with no wet egg mixture on it.
If the top starts to brown too quickly before the centre is set, loosely lay a sheet of foil over the dish for the last 10 minutes.
- 9
Remove from the oven and allow the casserole to rest for 5 full minutes before slicing. Scatter the fresh chopped parsley over the top just before serving.
Patience here pays off. The rest period lets the egg proteins finish setting so each slice holds its shape cleanly.
Nutrition per serving
285kcal
Calories
38g
Protein
7g
Carbs
11g
Fat
2g
Fibre
4g
Sugar
480mg
Sodium
Pro Tips
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Blending the cottage cheese smooth is the single biggest upgrade you can make. It creates a creamy custard texture that no one will identify as cottage cheese.
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Use a kitchen scale to measure your shredded chicken. 500g of cooked chicken sounds like a lot but it compresses beautifully into the casserole.
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Rotisserie chicken from the supermarket saves significant time on a busy weeknight when you are prepping this for the week ahead.
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Do not skip greasing the dish generously. A well-greased ceramic dish means the casserole will slide out cleanly and portions stay intact.
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Fresh herbs added at the end, like parsley or chives, make the whole dish taste brighter and more restaurant-quality with almost no extra effort.
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If you prefer a slightly crispier top, switch your oven to the grill or broil setting for the final 2 minutes of cooking.
Frequently Asked Questions
Variations
- •
Mediterranean Style
Add 60g of sliced sun-dried tomatoes, a handful of pitted kalamata olives, and a teaspoon of dried thyme alongside the oregano. Swap the cherry tomatoes for roasted red peppers from a jar, patted dry. The result is a deeply savoury, Mediterranean-inspired casserole with even more complex flavour.
- •
Dairy-Free Version
Replace the cottage cheese with 400g of silken tofu blended completely smooth. Swap the feta for a dairy-free feta alternative or simply omit it and add an extra tablespoon of nutritional yeast for a savoury, cheesy note. The casserole will have a slightly firmer texture but still holds together well and remains very high in protein.
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Spicy Harissa Kick
Stir 2 tablespoons of harissa paste into the egg and cottage cheese mixture before combining everything. The harissa adds warmth, depth, and a gorgeous red hue throughout the casserole. Top with a small dollop of plain Greek yogurt when serving to balance the heat.
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Artichoke and Chicken Upgrade
Add one 400g can of artichoke hearts, drained and roughly chopped, to the mixing bowl along with the spinach and chicken. The artichokes add fibre, a subtle earthy flavour, and make the casserole even more filling. This variation works particularly well with goat cheese instead of feta.
Substitutions
- •Cottage cheese → Plain Greek yogurt (Use full-fat Greek yogurt blended smooth for a similarly creamy, high-protein base. The flavour will be slightly tangier but works well with the feta and chicken.)
- •Cooked chicken breast → Cooked turkey breast (Turkey breast has a very similar protein and calorie profile to chicken and works identically in this recipe. Leftover roast turkey is an excellent option.)
- •Baby spinach → Kale or Swiss chard (Remove the tough stems and chop finely before wilting. Kale has a slightly more robust flavour and higher fibre content, so it makes the casserole even more nutritious.)
- •Feta cheese → Goat cheese or part-skim mozzarella (Goat cheese crumbles similarly to feta and adds a mild creaminess. Mozzarella gives a meltier finish and a milder overall flavour.)
- •Cherry tomatoes → Roasted red pepper strips (Pat them dry thoroughly from the jar before using. They add sweetness and colour without releasing extra moisture into the casserole during baking.)
🧊 Storage
Store leftover casserole slices in airtight containers in the refrigerator for up to 4 days. To freeze, wrap individual slices tightly in cling film then place in a freezer-safe bag. Freeze for up to 2 months. Thaw overnight in the refrigerator before reheating in the microwave for 2 minutes or in a 180C oven for 10 to 12 minutes until heated through.
📅 Make Ahead
Assemble the full casserole up to 12 hours ahead, cover tightly with cling film, and refrigerate unbaked. Remove from the fridge while the oven preheats the next morning. Bake as directed, adding approximately 5 extra minutes to account for the cold start. The flavour improves noticeably after an overnight rest as the herbs and garlic infuse through the egg and chicken mixture.
