Peel and slice potatoes very thin. Combine garlic, butter, potatoes, half and half, salt, pepper and nutmeg in a large pot. Bring to a boil and then lower heat to medium-high. Cook until thickened, around 5 minutes.
Combine ground beef, egg and seasonings of your choice. Roll into meatballs. Brown in skillet. Mix meatballs with potatoes and transfer to casserole dish. Bake for 1 hour, basting on occasion.