Preheat Your Oven: Start by preheating your oven to 350°F (175°C).
Cook the Sausage: In a large skillet over medium heat, cook the sausage until it's browned and crumbled. Make sure to drain the excess fat to keep the dish from getting too greasy.
Prepare the Grits: In a saucepan, bring 4 cups of water to a boil. Slowly stir in the grits and reduce the heat to low, cooking for about 5 minutes until thickened.
Mix Ingredients: In a large bowl, combine the cooked grits, browned sausage, shredded cheddar cheese, milk, eggs, salt, pepper, garlic powder, and onion powder. Stir well until all ingredients are evenly mixed.
Transfer to Baking Dish: Pour the mixture into a greased 9x13 inch baking dish, spreading it out evenly.
Bake: Place the dish in the preheated oven and bake for 30–35 minutes, or until the casserole is set and golden on top.
Cool and Serve: Allow it to cool for a few minutes before slicing and serving.