8 cups bread cubes (firm white bread, crust trimmed off)
8 ounces shredded sharp cheddar
1 cup sliced mushrooms
1 cup broccoli florets
6 large eggs
1½ cups milk
1 tsp. Dijon mustard
½ tsp. Worcestershire sauce
½ tsp. salt
¼ tsp. black pepper
In a large skillet, heat the oil and cook the sausage. Add chopped onion and cook until turkey is browned and crumbled, and onion is soft. Drain well on paper towels.
Butter a glass baking dish (13 ½ by 8 ¾ by 1 ¾ inches). In it, arrange half of the bread cubes. Sprinkle the cubes with half of the cheese. Continue with a layer of sausage, mushrooms and broccoli. Top with the remaining bread crumbs.
In a bowl, whisk together the eggs, milk, Dijon mustard, Worcestershire sauce, salt and pepper. Pour this mixture over the strata. Cover and chill for 1 hour or overnight.
To prepare for serving:
Bring strata to room temperature and let stand for 45 minutes. Preheat oven to 350 degrees.
Place the strata dish in a larger baking pan and add enough water to the pan to reach halfway up the sides of the strata dish. Bake for about 45 minutes, then sprinkle on the remaining cheese and continue baking until the strata sets and the cheese melts.
Pipe sour cream on top of the strata, or let guests add it as they wish.