Make-Ahead Christmas Breakfast Casserole: Sausage, Egg and Cheddar

A make-ahead breakfast casserole is the answer to every busy holiday morning: you assemble it the night before, slide it into the oven while the coffee brews, and serve a golden, cheesy, sausage-studded egg bake to a crowd. Think of it as a savory bread pudding, soft and custardy in the middle with crisp, cheesy edges. With Christmas four weeks away and Thanksgiving guests to feed first, it is worth bookmarking now.

Why it works

Cubed bread soaks up a seasoned egg-and-milk custard overnight, so it bakes up tender instead of dry or rubbery. Everything happens in one baking dish, and the leftovers reheat beautifully, which makes it ideal for houseguests, brunch parties and school-holiday mornings.

Tips for the best result

• Use sturdy, slightly stale bread. Day-old French bread, sourdough or brioche holds its shape. For extra insurance, toast the cubes in a 300°F (150°C) oven for 10 minutes.
• Brown the sausage well and drain it, so the casserole is flavorful but not greasy.
• Whisk the custard thoroughly with a little mustard powder; it sharpens the cheese without tasting like mustard.
• Let it rest overnight (at least 4 hours). This is what turns it from scrambled eggs on toast into a proper casserole.
• Take it out of the fridge 20 minutes before baking so the center cooks through at the same time as the top.
• Check doneness: a knife in the center should come out clean and the middle should not jiggle. The internal temperature should reach 160°F (71°C).

Variations

• Vegetarian: swap the sausage for sautéed mushrooms, spinach and roasted red pepper.
• Ham and Swiss: use diced ham and Gruyère or Swiss cheese.
• Christmas colors: fold in chopped red pepper and baby spinach for red and green flecks.
• Persian-inspired: add a handful of chopped dill, parsley and chives and crumbled feta, then serve with sliced cucumber and tomato, much like a kuku sabzi.

Serving ideas for a holiday brunch

Serve squares with a bright fruit salad, roasted potatoes, a pot of coffee or tea and a sparkling mocktail. A little hot sauce or tomato chutney on the side lets everyone season their own plate.

Storage and reheating

Cover and refrigerate leftovers for up to 4 days. Reheat single portions in the microwave for about 60 seconds or in a 325°F (160°C) oven until hot. Baked squares freeze well for up to 2 months; thaw overnight in the fridge. Keep the unbaked, assembled casserole refrigerated for no more than 24 hours.

Food safety note: raw eggs and sausage need proper cooking, so bake until the center is fully set, and take extra care when serving pregnant guests, older adults and young children.