Plop the other half of the mixture, followed by the rest of your cheese, then breadcrumbs. I like to spray the top with oil (you could also dot it with tiny pieces of butter). Put the casserole in the oven for at least 30 minutes. Wait for it to be bubby and get brown on the top. I like to broil it for 2 minutes at the end, just to make the top nice and brown.