Ground sausage (whether made from pork, chicken, turkey, or a mix) has the perfect texture for casseroles! Pick one with a flavor profile you love, then go from there. If you have plain ground pork and want to add breakfast seasoning, this is a great keto-friendly breakfast sausage recipe. You can use hot sausage and pepper jack for spice lovers, Italian sausage and mozzarella for a Mediterranean vibe, or chicken apple sausage with gouda for a sweet-and-savory flavor!