Breakfast Casserole with Italian Sausage and Fontina

We wanted a flavorful casserole with a crisp top and a soft, custardy inside. Here’s what we discovered:

Test Kitchen Discoveries

• Even when staled in the oven overnight, white bread soaked up too much custard and turned to mush. Toasted Italian bread greatly improved the texture.
• Using whole milk instead of half-and-half or cream kept the casserole light and fluffy; incorporating a minimal amount ensured the dish remained firm.
• You want enough cheese and sausage to flavor the dish, but not so much that you are left with a greasy, soggy mess.
• Some recipes we tasted contained pockets where certain ingredients tended to congregate. We staggered the bread, sausage, and cheese mixtures in multiple layers. Building the casserole with care helped ensure every bite had flavor.
• To guarantee the custard soaked in evenly, we covered the prepared casserole with plastic wrap and weighed it down for up to 24 hours.