Chicken fajitas taste great straight from a hot skillet, but standing over the stove and cooking everything in small batches can feel like a lot on a busy night. This Chicken Fajita Casserole keeps the familiar chicken, peppers, onions, fajita seasoning, and melted cheese, then brings them together in one warm baking dish.
The method is beginner-friendly because each part is handled in order. You will cut the chicken into even pieces so it cooks at the same rate, soften the vegetables before baking, and use a creamy filling that helps keep the casserole from drying out in the oven.
Plan on about 15 minutes of prep and 25 to 30 minutes of cooking, depending on how quickly your chicken browns. A 9 × 13-inch baking dish works best because it gives the filling enough room to heat evenly without becoming too deep or watery.
You do not need any special equipment. A skillet, sharp knife, cutting board, mixing spoon, and baking dish will get the job done. Once it comes out of the oven, give it a few minutes to settle before serving so the creamy filling stays around the chicken instead of running across the plate.
- 1½ lb boneless, skinless chicken breasts
- 2 bell peppers, any colors
- 1 medium yellow or red onion
- 2 tablespoons olive oil, divided
- 2 tablespoons fajita seasoning
- 4 oz cream cheese, softened
- ½ cup sour cream
- 1½ cups shredded Mexican-blend cheese
- 9 × 13-inch baking dish
- Large skillet
- Cutting board
- Sharp kitchen knife
- Large mixing spoon
- Measuring spoons
- Measuring cup
- Preheat the oven to 375°F.
- Grease the baking dish.
- Cut the chicken into even pieces.
- Slice the peppers and onion into thin strips.
- Coat the chicken with fajita seasoning.
- Brown the chicken in a hot skillet.
- Soften the peppers and onion.
- Mix the creamy fajita filling.
- Transfer the filling to the baking dish.
- Cover the casserole with shredded cheese.
- Bake until hot and bubbling.
- Rest the casserole before serving.
Preheat the oven to 375°F
Set the oven to 375°F (190°C) before you start cutting anything. Giving the oven enough time to reach the correct temperature means the casserole will begin cooking as soon as it goes in. If your oven usually heats slowly, allow around 10 to 15 minutes for preheating. Place an oven rack in the center position so heat can move around the baking dish evenly.
Grease the baking dish
Coat the inside of a 9 × 13-inch baking dish with a thin layer of cooking spray or about 1 teaspoon of olive oil. Cover the bottom and corners, where melted cheese and creamy sauce tend to stick most. A slightly smaller dish can work, but the casserole will be deeper and may need a few extra minutes in the oven.
Cut the chicken into even pieces
Aim for pieces about 1 inch wide so they cook at roughly the same speed. Put the chicken on a clean cutting board and trim away any large pieces of fat before cutting. Pieces that are much bigger than the rest can stay raw in the center while smaller ones become dry. Keep the raw chicken separate from the vegetables, and wash the knife and board before using them for anything that will not be cooked.
Cut the chicken into even pieces
Aim for pieces about 1 inch wide so they cook at roughly the same speed. Put the chicken on a clean cutting board and trim away any large pieces of fat before cutting. Pieces that are much bigger than the rest can stay raw in the center while smaller ones become dry. Keep the raw chicken separate from the vegetables, and wash the knife and board before using them for anything that will not be cooked.
Slice the peppers and onion into thin strips
Cut 2 bell peppers in half, remove the seeds and white ribs, then slice them into strips about ¼ inch thick. Peel 1 medium onion and cut it into strips about the same width. Keeping the vegetables close in size helps them soften at the same rate. Very thick pieces can stay firm after baking, while paper-thin strips may become limp before the casserole reaches the oven.
Coat the chicken with fajita seasoning
Put the cut chicken in a medium bowl. Add 1 tablespoon olive oil and 2 tablespoons fajita seasoning, then toss until every piece has a light, even coating.
The oil helps the seasoning cling to the chicken instead of collecting in the bottom of the bowl. If your fajita seasoning contains a lot of salt, do not add extra salt yet. You can adjust the finished casserole after tasting it
Brown the chicken in a hot skillet
Heat a large skillet over medium-high heat for about 2 minutes. Add the seasoned chicken in a single layer and cook for 5 to 7 minutes, turning the pieces as they brown. The chicken does not need to develop a dark crust, but the outside should lose its raw pink color and pick up some golden spots.
For food safety, chicken should reach 165°F (74°C) internally by the time the finished casserole is served.
Soften the peppers and onion
Add the remaining 1 tablespoon olive oil to the same skillet and lower the heat to medium. Add the sliced peppers and onion and cook for 4 to 5 minutes, stirring a few times.
Stop when the onion looks slightly translucent and the peppers have softened around the edges but still hold their shape. They will continue cooking in the oven, so do not let them turn completely soft. Transfer the vegetables to a large mixing bowl with the browned chicken.
Stir the creamy fajita filling together
Add 4 ounces softened cream cheese, ½ cup sour cream, and ½ cup shredded Mexican-blend cheese to the bowl with the chicken and vegetables. Stir until everything is coated in a creamy layer and the cream cheese is no longer sitting in large lumps.
Room-temperature cream cheese mixes much more smoothly. If yours is still cold, cut it into small cubes and let it sit out for about 10 minutes before stirring.
Spread the mixture evenly in the baking dish
Spoon the filling into the prepared 9 × 13-inch baking dish and spread it into an even layer. Push the chicken and vegetables toward the corners instead of leaving a thick mound in the center.
An even layer matters because the outside edges heat faster than the middle. If one part is much deeper, the center can stay cooler while the edges begin to dry out. Keep the surface fairly level so the cheese in the next step melts evenly across the whole casserole.
Top the Chicken Fajita Casserole with shredded cheese
Sprinkle the remaining 1 cup shredded Mexican-blend cheese evenly over the filling. Cover the center and edges so every serving gets some melted cheese.
Mexican blend works well, but cheddar, Monterey Jack, or pepper Jack can be used instead. Pepper Jack adds a little more heat. Avoid piling most of the cheese in the center, since a thick layer there can melt more slowly than the rest.
Bake until hot and bubbling
Place the uncovered baking dish on the center oven rack and bake at 375°F (190°C) for 18 to 22 minutes. Look for bubbling around the edges and fully melted cheese across the top.
If you want a lightly browned surface, move the dish under the broiler for 1 to 2 minutes after baking. Stay nearby while broiling because cheese can go from golden to burnt quickly.
The chicken should reach 165°F (74°C) in the thickest pieces before serving.
Rest the casserole before serving
Leave the casserole on a heat-safe surface for 5 to 10 minutes after removing it from the oven. The creamy filling will look looser while it is very hot, then thicken slightly as it rests.
Serving immediately can leave extra liquid on the plate, especially because peppers and onions release moisture as they cook. Once rested, spoon the casserole onto plates and serve it as-is or with tortillas, rice, avocado, salsa, or a squeeze of fresh lime.
- 1½ lb boneless, skinless chicken breasts
- 2 bell peppers
- 1 medium onion
- 2 tablespoons olive oil
- 2 tablespoons fajita seasoning
- 4 oz cream cheese
- ½ cup sour cream
- 1½ cups shredded Mexican-blend cheese
- Preheat the oven to 375°F.
- Grease a 9 × 13-inch baking dish.
- Cut the chicken into 1-inch pieces.
- Slice the peppers and onion.
- Season the chicken.
- Brown the chicken for 5 to 7 minutes.
- Cook the vegetables for 4 to 5 minutes.
- Mix in cream cheese, sour cream, and cheese.
- Spread the filling in the baking dish.
- Add the remaining cheese.
- Bake for 18 to 22 minutes.
- Rest for 5 to 10 minutes before serving.
Oven: 375°F (190°C)
Difficulty: Beginner
CONCLUSION
Enjoy Your Chicken Fajita Casserole
You now have a creamy Chicken Fajita Casserole with tender chicken, soft peppers, onions, fajita seasoning, and plenty of melted cheese.
The key is keeping the chicken pieces even, cooking the vegetables only until partly soft, and giving the finished casserole a few minutes to rest before serving.
Serve it with warm tortillas, rice, avocado, salsa, or your favorite fajita toppings.
Save this recipe to your Pinterest dinner board so you can find it the next time you need a warm, filling weeknight meal.
Ingredients
Tap items as you use themEquipment
Method
Your progress is saved on this device- Preheat the oven to 375°F (190°C) and place a rack in the center.
- Lightly coat a 9 × 13-inch baking dish with cooking spray or 1 teaspoon olive oil.
- Trim the chicken and cut it into pieces about 1 inch wide.
- Cut the bell peppers and onion into strips about ¼ inch thick.
- Toss the chicken with 1 tablespoon olive oil and 2 tablespoons fajita seasoning until evenly coated.
- Heat a large skillet over medium-high heat and cook the chicken for 5-7 minutes, turning as needed, until lightly browned.
- Add the remaining 1 tablespoon olive oil to the skillet and cook the peppers and onion over medium heat for 4-5 minutes, until slightly softened.
- Place the chicken and vegetables in a large mixing bowl, then add the softened cream cheese, sour cream, and ½ cup shredded cheese. Stir until evenly coated.
- Spread the chicken mixture evenly in the prepared baking dish.
- Sprinkle the remaining 1 cup shredded cheese evenly over the top.
- Bake uncovered at 375°F (190°C) for 18-22 minutes, until hot and bubbling and the cheese has melted.
- Check that the thickest pieces of chicken have reached an internal temperature of 165°F (74°C).
- Let the casserole rest for 5-10 minutes before serving.
Chef’s Notes
- Use softened cream cheese so it blends smoothly into the filling.
- Cook the peppers only until slightly softened because they will continue cooking in the oven.
- Packaged fajita seasoning can contain plenty of salt, so taste before adding extra salt.
- For more heat, use pepper Jack cheese or add a small amount of cayenne or chili flakes.
- For less heat, use mild fajita seasoning and Monterey Jack or cheddar cheese.
- For a browned top, broil the finished casserole for 1-2 minutes, watching it closely.
- To use cooked chicken, replace the raw chicken with about 3 cups chopped or shredded cooked chicken and skip the browning step.
- The casserole can be assembled, covered, and refrigerated for up to 24 hours before baking.
- Store leftovers covered in the refrigerator for 3-4 days.
- Serve with warm tortillas, rice, cauliflower rice, avocado, salsa, cilantro, lime wedges, or a green salad
