“One of the hardest things for an innkeeper or hostess is finding an egg recipe that will hold well. This one will keep on the table for about an hour!” River Bend Farm, Williamstown, Massachusetts
Whisk the milk, eggs, and mustard in a bowl and set aside.
Butter an 8-cup-capacity oval gratin dish or other suitable refrigerator-to-oven-to-table container. Cover the bottom with half the stuffing mix or bread pieces.
In a medium-sized saucepan, boil the sausage briefly in water. Drain in a colander, breaking up the meat, and let cool. Distribute the meat in an even layer over the top of the stuffing or bread, spread the spinach over that, and gently pour the egg-milk mixture over all. Grind pepper over the top and sprinkle with the cheese. Cover with plastic wrap and refrigerate 8 hours or more.
Bake in a preheated 350 degree oven for 60 to 75 minutes or until the top is brown and puffy. Serve immediately.
VARIATION: Substitute ham for sausage, shredded zucchini for spinach, change the cheese, add a little nutmeg; it’s versatile, easy, and fun. The important things are to use what’s seasonally available, use the 2 eggs to 1 cup milk custard ratio, and allow the casserole to sit for at least 8 hours to soak the bread and blend the flavors.