1. Preheat oven to 350°F (175°C).
2. Season chicken breasts with salt, pepper, garlic powder, paprika, and optional onion powder or herbs.
3. Heat olive oil in a large skillet over medium-high heat. Brown chicken breasts 2-3 minutes per side without fully cooking. Remove and set aside.
4. In the same skillet, add butter or olive oil and sauté chopped onion and green bell pepper about 5 minutes until softened.
5. In a bowl, mix cream of chicken soup, cream of mushroom soup, chicken broth, and uncooked rice until smooth. Add cornstarch mixture if a thicker sauce is desired.
6. Spread sautéed vegetables evenly in a baking dish, layer browned chicken on top.
7. Pour soup and rice mixture over the chicken, ensuring rice is submerged.
8. Cover tightly with foil and bake 60 minutes until rice is tender and chicken reaches 165°F.
9. For a golden top, remove foil during last 10 minutes of baking.
10. Let rest covered for 5-10 minutes before serving.