For an extra layer of flavor, consider adding some sauteed onions and peppers to the hash brown base. If you don't have half-and-half, you can use a mixture of milk and heavy cream. Feel free to experiment with different types of cheese in the filling. Make sure the hash browns are well-browned to create a sturdy crust. Watch the quiche carefully during baking to prevent the crust from burning. If it starts to brown too quickly, tent it with foil.