High-Protein Chicken Parmesan Casserole
Seared chicken pieces simmer briefly in marinara, then bake under mozzarella and Parmesan until the sauce bubbles around the skillet and the cheese melts. This Chicken Parmesan casserole has no breading, pasta, or vegetable base; it stays saucy and is served directly from the pan.
Browning the chicken and warming the sauce before baking give the casserole a short oven finish. Cut the chicken into even pieces and check its temperature rather than relying on bake time alone, especially if you use a smaller skillet or sear in batches.
Ingredients
- 1 1/2 pounds boneless, skinless chicken breasts, cut into uniform bite-size pieces (680g)
- 1 tablespoon olive oil
- 1 teaspoon fine salt, or to taste
- 1/2 teaspoon black pepper
- 1 teaspoon Italian seasoning
- 3 garlic cloves, minced
- 24 ounces marinara sauce, about 3 cups (680g)
- 1 1/2 cups shredded low-moisture mozzarella, preferably freshly shredded (170g)
- 1/3 cup finely grated Parmesan, plus more for serving if desired (30g)
- 2 tablespoons chopped fresh parsley
For mild heat, add 1/4 teaspoon red pepper flakes with the garlic. A thick marinara helps the sauce stay glossy rather than soupy.
How to Make Chicken Parmesan Casserole
- Preheat and season: Heat the oven to 375°F (190°C). Season the chicken evenly with the salt, pepper, and Italian seasoning.
- Brown the chicken: Heat the olive oil in a 10- to 12-inch oven-safe skillet over medium-high heat. Add the chicken in a mostly single layer and turn it as it browns, about 6–8 minutes total. Work in batches if needed so moisture can escape and the pieces brown instead of steam. The chicken does not need to be fully cooked yet.
- Warm the sauce: Reduce the heat to medium. Add the garlic and stir briefly until fragrant, without letting it brown. Stir in the marinara and cook for 2–3 minutes, until the sauce is steaming around the edges.
- Add the cheese: Turn off the heat. Scatter the mozzarella over the chicken, leaving some sauce visible around the edge, then sprinkle the Parmesan on top.
- Bake: Transfer the uncovered skillet to the oven. Begin checking after 10 minutes; baking usually takes about 10–15 minutes. The sauce should bubble at the edges, and the cheese should be fully melted with a few light golden spots. Check several of the largest chicken pieces with an instant-read thermometer; they must reach 165°F (75°C).
- Rest and serve: Scatter the parsley over the cheese. Let the casserole rest for 5 minutes so the bubbling sauce settles, then serve from the skillet.
Check that both the skillet and its handle are oven-safe before baking. Skillet size and how hot the sauce is when it goes into the oven can change the bake time; remove the casserole once the chicken is cooked through rather than leaving it in for extra browning.
How to Keep the Sauce from Turning Watery
Use the listed amount of marinara without adding water. If you add vegetables, cook them first until their released liquid evaporates, or drain them before adding them to the skillet. Without a pasta or vegetable base to absorb sauce, this casserole should be spoonable and saucy, not soupy.
Using Cooked Chicken Instead
For a shortcut, replace the raw chicken with about 4 cups cooked, chopped or shredded chicken. Warm it in the marinara on the stovetop, add the cheeses, and bake just until the topping melts and the casserole is hot throughout. The oven finish will be shorter, and the chicken will be softer without the freshly seared flavor.
Serving and Storage
Serve with a green salad or roasted vegetables. Pasta, rice, or garlic bread can go alongside the skillet for anyone who wants a starch.
Cool leftovers promptly and refrigerate in an airtight container for 3–4 days. Reheat individual portions in short microwave intervals until hot. For a larger portion, cover and warm in a 350°F (175°C) oven until heated through; prolonged reheating can dry out the chicken.
Leftovers can be frozen in an airtight, freezer-safe container, though the sauce and cheese may change texture after thawing.
For another baked chicken dinner, try Chicken Alfredo Bake with Broccoli. For a different chicken dinner, see these High-Protein Chicken Enchilada Bowls.
Nutrition
Approximate nutrition per serving, based on 1/6 of the casserole: 330 calories, 36g protein, 15g fat, and 12g carbohydrates. Approximate nutrition per 100g: 130 calories, 14g protein, 6g fat, and 5g carbohydrates. Values vary with the marinara and cheese used.
Equipment
- 10- to 12-inch oven-safe skillet
- Instant-read thermometer
Ingredients
For the Casserole
- 1 1/2 pounds boneless, skinless chicken breasts, cut into uniform bite-size pieces (680 g)
- 1 tablespoon olive oil
- 1 teaspoon fine salt, or to taste
- 1/2 teaspoon black pepper
- 1 teaspoon Italian seasoning
- 3 garlic cloves, minced
- 24 ounces marinara sauce, about 3 cups (680 g)
- 1 1/2 cups shredded low-moisture mozzarella, preferably freshly shredded (170 g)
- 1/3 cup finely grated Parmesan, plus more for serving if desired (30 g)
- 2 tablespoons chopped fresh parsley
Instructions
- Preheat the oven to 375°F (190°C). Season the chicken with the salt, pepper, and Italian seasoning.
- Heat the olive oil in a 10- to 12-inch oven-safe skillet over medium-high heat. Add the chicken in a mostly single layer and brown, turning the pieces, for about 6–8 minutes total. Work in batches if needed; the chicken does not need to be fully cooked.
- Reduce the heat to medium. Add the garlic and stir briefly until fragrant, without browning it.
- Stir in the marinara and cook for 2–3 minutes, until steaming around the edges.
- Turn off the heat. Scatter the mozzarella over the chicken, leaving some sauce visible around the edge, then sprinkle with Parmesan.
- Bake the uncovered skillet for about 10–15 minutes, beginning to check after 10 minutes. Remove it when the sauce bubbles, the cheese has melted, and the largest chicken pieces reach 165°F (75°C) on an instant-read thermometer.
- Scatter the parsley over the cheese. Rest for 5 minutes before serving.
Tips
- Cut the chicken into evenly sized pieces so they cook at the same rate.
- Sear the chicken in batches if needed to help it brown instead of steam.
- Use a thick marinara and avoid adding water to keep the casserole saucy rather than soupy.
- Check the temperature of several of the largest chicken pieces; do not rely on baking time alone.
- Confirm that both the skillet and its handle are oven-safe before baking.
Variations
- Mild Heat: Add 1/4 teaspoon red pepper flakes with the garlic.
- Cooked Chicken Shortcut: Use about 4 cups cooked, chopped or shredded chicken. Warm it in the marinara, add the cheeses, and bake just until hot throughout and the topping melts.