This high-protein Greek chicken casserole combines tender chicken, creamy feta, and Mediterranean vegetables for a satisfying weeknight meal. Ready in under 30 minutes, it's packed with protein and perfect for…

Ingredients

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Instructions

Step 1

Preheat your oven to 400°F (200°C). While the oven heats, prepare all your ingredients. Cubing the chicken into uniform 1-inch pieces ensures even cooking—if pieces vary in size, some will be dry while others remain undercooked. Pat the chicken dry with paper towels; moisture inhibits browning, and we want those golden-brown edges for maximum flavor. Slice the red onion thinly so it softens quickly and almost melts into the dish. Mince the garlic finely—larger pieces can burn and become bitter. Dice the bell peppers into small, even cubes (about 1/2 inch) so they cook through in the same time as the chicken. Halve the cherry tomatoes; if they are very large, quarter them. Halve the olives so their briny flavor disperses throughout the casserole.

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Step 2

In a large skillet (oven-safe if you want to use the same pan for the casserole, but a separate baking dish works too), heat 2 tablespoons of olive oil over medium-high heat until shimmering. Add the chicken cubes in a single layer—do not overcrowd the pan; if needed, cook in two batches. Sear the chicken without moving it for 3-4 minutes until the bottom is deeply golden. Flip and cook another 2-3 minutes. The chicken should be browned on the outside but not fully cooked through; it will finish in the oven. Transfer the seared chicken to a plate. The browning (Maillard reaction) creates hundreds of flavor compounds that make the casserole taste rich and savory.

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Step 3

Reduce the heat to medium and add the sliced red onion to the same skillet (no need to clean it—the browned bits add flavor). Sauté for 2 minutes until the onion softens and becomes translucent. Add the minced garlic and cook for 30 seconds until fragrant, stirring constantly to prevent burning. Then add the diced bell peppers and cook for 3 minutes, stirring occasionally, until they begin to soften. The peppers should still have a slight crunch because they will continue cooking in the oven.

Step 4

Add the halved cherry tomatoes and Kalamata olives to the skillet. Sprinkle the dried oregano, thyme, salt, and pepper over the vegetables. Stir everything together and cook for 2 minutes, until the tomatoes start to release their juices and the herbs become aromatic. Squeeze the lemon juice over the mixture and stir. Remove the skillet from heat.

Step 5

Return the seared chicken to the skillet (or transfer the vegetable mixture to a 9×13-inch baking dish if your skillet isn’t oven-safe). Nestle the chicken pieces among the vegetables. Sprinkle the crumbled feta cheese evenly over the top. The feta will melt and become creamy in the oven, creating a luscious sauce that coats the chicken and vegetables. For an extra touch, you can add a few whole olives and tomato halves on top for presentation.

Step 6

Place the skillet or baking dish in the preheated oven. Bake for 15-20 minutes, until the chicken is cooked through (internal temperature of 165°F/74°C) and the feta is melted and lightly golden on the edges. The vegetables should be tender but not mushy. If you prefer a browned top, switch the oven to broil for the last 1-2 minutes, watching closely to avoid burning. Remove from the oven and let rest for 5 minutes. Garnish with fresh parsley before serving. Serve the casserole warm, spooned over rice, quinoa, or with crusty bread to soak up the delicious juices. For a low-carb option, serve with a side of roasted vegetables or a Greek salad.

For best results

  • For the best texture and flavor, use high-quality feta cheese from a block (not pre-crumbled). Block feta is creamier and less dry, and it melts into a velvety sauce. Look for feta made from sheep's milk or a sheep-goat blend for authentic Greek taste. If you can't find block feta, you can still use crumbled, but reduce the amount slightly as it tends to be saltier.
  • To ensure the chicken stays juicy, do not overcook it. The internal temperature should reach 165°F (74°C). Use an instant-read thermometer for accuracy. If you don't have one, cut into the largest piece—the juices should run clear and the meat should be opaque throughout.
  • Feel free to customize the vegetables based on what you have on hand. Zucchini, eggplant, or artichoke hearts would be wonderful additions. Just adjust the cooking time accordingly—zucchini cooks quickly, while eggplant may need a few extra minutes.
  • This casserole is perfect for meal prep. Prepare the entire dish, let it cool, and divide into airtight containers. It will keep in the refrigerator for up to 4 days. Reheat in the microwave or oven at 350°F (175°C) until warmed through. The flavors actually meld and improve overnight.
  • To make this dish dairy-free, simply omit the feta cheese or use a high-quality vegan feta alternative. The casserole will still be flavorful thanks to the olives, lemon, and herbs. You may want to add a tablespoon of nutritional yeast for a cheesy flavor.
  • For a spicier kick, add a pinch of red pepper flakes or a diced jalapeño along with the bell peppers. The heat complements the briny olives and creamy feta beautifully.
  • If you prefer a more saucy casserole, add 1/4 cup of chicken broth or white wine to the skillet after cooking the vegetables. Let it simmer for a minute to reduce slightly before adding the chicken and feta. This will create extra juices to spoon over rice or pasta.

Variations

  • For a low-carb/keto version, skip any starchy sides and serve the casserole over cauliflower rice or zucchini noodles. You can also add extra vegetables like spinach or kale—stir in a couple of handfuls during the last few minutes of cooking until wilted. The feta provides enough richness to keep it satisfying.
  • Try a Mediterranean twist by adding 1/2 cup of drained and rinsed chickpeas along with the vegetables. This boosts the fiber and protein content even further. You could also swap the chicken for 1.5 pounds of peeled and deveined shrimp—reduce the baking time to 10-12 minutes since shrimp cook quickly.
  • For a vegetarian version, replace the chicken with 1.5 pounds of firm tofu, cubed and pressed dry, or use a combination of chickpeas and artichoke hearts. Sear the tofu similarly to the chicken for a crispy exterior. The feta and olives provide ample flavor, so you won't miss the meat.
  • Make it a one-pan meal by adding 1 cup of uncooked orzo or rice to the skillet after searing the chicken. Sauté the orzo for a minute, then add 1.5 cups of chicken broth and bring to a simmer. Nestle the chicken back in, top with feta, and bake covered for 25-30 minutes until the grains are tender. This creates a complete meal in one dish.

Nutrition

  • Calories385 kcal
  • Total Fat22g
  • Saturated Fat8g
  • Cholesterol115mg
  • Sodium890mg
  • Total Carbohydrates10g
  • Dietary Fiber2g
  • Sugars5g
  • Protein38g

Common Questions

Can I use chicken thighs instead of breasts?
Absolutely! Chicken thighs are more forgiving and stay juicy even if slightly overcooked. Use boneless skinless thighs and cut them into similar-sized cubes. The cooking time may remain the same, but check for doneness at 165°F (74°C). Thighs have a slightly higher fat content, which adds richness to the casserole.
How do I store leftovers?
Allow the casserole to cool completely, then transfer to an airtight container. It will keep in the refrigerator for up to 4 days. To reheat, microwave individual portions for 1-2 minutes or reheat in a 350°F (175°C) oven for about 10-15 minutes until warmed through. The feta may become slightly more firm upon reheating, but the flavors will be even more developed.
Can I freeze this casserole?
Yes, this casserole freezes well. Assemble the dish completely but do not bake. Cover tightly with foil and freeze for up to 3 months. When ready to eat, thaw overnight in the refrigerator, then bake as directed, adding 10-15 minutes to the baking time since it starts cold. Alternatively, you can freeze baked leftovers in individual portions for quick lunches.
What can I substitute for Kalamata olives?
If you don’t have Kalamata olives, you can use black olives, green olives, or even capers for a similar briny flavor. Olives are key to the Greek character of the dish, but if you’re not a fan, simply omit them. You might add an extra squeeze of lemon or a pinch of salt to compensate for the lost saltiness.
Is this dish gluten-free?
Yes, this Greek chicken casserole is naturally gluten-free as written. All the ingredients are gluten-free. However, if you serve it with pasta or bread, choose gluten-free options if needed. Always check labels on ingredients like feta (some brands may add anti-caking agents that contain gluten, though it’s rare).
Can I make this in a slow cooker or Instant Pot?
For a slow cooker, sear the chicken and sauté the vegetables as directed, then transfer everything to the slow cooker. Cook on low for 4-6 hours or high for 2-3 hours. Add the feta during the last 30 minutes of cooking. For an Instant Pot, use the sauté function for searing and sautéing, then pressure cook on high for 5 minutes with a quick release. The texture will be softer, but still delicious.
What sides go well with this casserole?
This casserole pairs wonderfully with rice (white, brown, or cauliflower), quinoa, couscous, or crusty bread to soak up the juices. A simple Greek salad with cucumber, tomato, and red onion adds freshness. For a low-carb option, serve with roasted vegetables like asparagus or broccoli.
How can I reduce the sodium?
To lower sodium, use low-sodium chicken broth if adding liquid, reduce the salt in the recipe, and choose olives that are packed in water (rinsed) rather than brine. Also, opt for a less salty feta cheese (some brands have lower sodium options). You can also increase the amount of fresh herbs like oregano and parsley to boost flavor without salt.