Stir the half & half and milk together in a large skillet. Bring the mixture to a rolling boil, stir in the grits and butter, then reduce the heat to medium low.
1 cup half & half, 3 cups milk, 1 cup uncooked grits, 1/2 stick butter
Let the grits simmer, stirring occasionally, covered for 5-7 minutes.
Stir the beaten egg into the grits mixture. Once evenly incorporated, stir in the cheeses. Continue stirring until the mixture's smooth, and the cheeses evenly incorporated.
1 cup shredded sharp cheddar cheese, 1 cup shredded Monterrey Jack cheese, 1 large egg, beaten, 1/4 cup shredded Parmesan cheese
Season the mixture with the garlic, and salt & pepper, to taste.
1 tsp garlic powder, salt & pepper, to taste
Lightly spray a 9x13 baking dish with non stick cooking spray. Transfer the mixture to the prepared dish. Use a spatula to smooth the mixture out evenly into the dish.
Bake at 350 degrees for 20-25 minutes, or until cooked through and golden brown on top.
Let the casserole rest 2-3 minutes before serving. Serve, as is, or with breakfast sausage, eggs, hash browns- your favorite breakfast fixins.