Season your chicken breasts with salt and pepper on both sides.
In a large skillet, heat olive oil over medium-high heat. Sear the chicken breasts for about 4–5 minutes per side, until golden brown. You don’t need to cook them through completely — they’ll finish in the oven. Once browned, remove the chicken and set it aside.
3. Sauté the Vegetables
In the same skillet (no need to wash it — those leftover bits add flavor!), toss in your diced onion, minced garlic, diced bell pepper, and sliced mushrooms.
Sauté everything for 5 to 7 minutes, or until the vegetables are soft, tender, and fragrant. This step adds a wonderful depth of flavor to the casserole.
4. Mix the Filling
In a large mixing bowl, combine the sautéed vegetables with:
- 1 cup frozen peas
- 1 cup frozen corn
- 1 can of cream of chicken soup
- 1 cup chicken broth
- 1 cup sour cream
- 1 cup shredded cheddar cheese
Stir everything together until it’s well-mixed and creamy. This is your flavorful, veggie-packed base.
5. Assemble the Casserole
Pour the vegetable mixture into the greased baking dish and spread it out evenly. Gently lay the seared chicken breasts on top.
Don’t worry if they’re a little underdone — they’ll finish cooking as the casserole bakes.
