01 - Preheat oven to 400°F. Grease a 9×13-inch baking dish with olive oil or nonstick cooking spray.
02 - Pat chicken breasts dry with paper towels. Season both sides generously with salt, pepper, paprika, and dried thyme, pressing the spices into the meat to adhere.
03 - In a large skillet over medium heat, melt the butter with olive oil. Add sliced mushrooms and cook for 4-5 minutes, stirring occasionally, until softened and lightly browned. Add minced garlic and cook for 1 additional minute until fragrant.
04 - Remove skillet from heat. Arrange seasoned chicken breasts in a single layer in the prepared baking dish. Spread sautéed mushrooms evenly over the chicken pieces. Carefully pour chicken broth around the base of the chicken, not directly over the top.
05 - Sprinkle shredded mozzarella and grated Parmesan cheese evenly over the chicken and mushrooms, covering completely.
06 - Bake uncovered for 25-30 minutes, or until chicken reaches an internal temperature of 165°F and cheese is bubbly and golden brown on top.
07 - Let the dish rest for 5 minutes before serving to allow juices to redistribute. Garnish with fresh thyme or parsley if desired. Serve hot alongside rice, mashed potatoes, or pasta.