Creamy, easy, and so very tasty, this casserole can be made ahead of time and can be changed depending on the cheese and veggies used. It’s great for a brunch, lunch, or easy dinner and a great way to use up leftover ham.
Preheat oven to 350 degrees F (175 degrees C). Grease a 3-quart baking dish.
Heat olive oil in a large skillet over medium heat; cook and stir mushrooms, onion, and bell pepper in hot oil until onions are translucent, about 5 minutes. Transfer vegetables to a large bowl.
Stir hash brown potatoes, ham, cream of chicken soup, sour cream, about 3/4 cup Cheddar cheese, and about 3/4 cup Parmesan cheese into vegetables. Spread potato mixture into the prepared baking dish. Sprinkle remaining 1/4 cup Cheddar cheese and 1/4 cup Parmesan cheese over potato mixture.
Bake in the preheated oven until bubbly and cheese is melted, 40 to 45 minutes. Let stand for 5 minutes before serving.
Per Serving: 612 calories; protein 28.2g; carbohydrates 33.2g; fat 48.5g; cholesterol 93.2mg; sodium 1544.6mg.