Preheat oven to 375°F (190°C). Lightly grease a 9x13-inch baking dish.
Season chicken breasts with salt and pepper. Heat olive oil in a skillet over medium heat and sear the chicken for 2-3 minutes per side until golden. Remove from heat.
In a mixing bowl, whisk together the cream of mushroom soup, sour cream, milk, garlic powder, onion powder, and paprika.
Place the seared chicken breasts in the prepared baking dish. Scatter sliced mushrooms over the top.
Pour the soup mixture evenly over the chicken and mushrooms. Sprinkle with mozzarella cheese.
Bake uncovered for 25-30 minutes, or until the chicken is cooked through and the sauce is bubbly.
Garnish with fresh parsley before serving.