Place croutons in greased 13x9x2 inch pan. Saute vegetables lightly in oil (with a bit of garlic if desired). Top croutons with cheese and sautéed vegetables.
Beat eggs with 2 cups milk and seasonings; pour over vegetables. Cover and refrigerate overnight.
Mix soup and ½ cup milk and spread on top before you bake. Bake at 325 degrees for one hour.