I didn’t grow up eating many casseroles; the main event at my family’s holiday brunch was bagels and lox. So, the first time I encountered a breakfast casserole at a New Year’s Day shindig, I was dubious. Where was the Nova and whitefish salad? Or at least the coffee cake and French toast I associated with parties held before noon?
One bite of that golden-topped casserole, though, set me straight. Bits of crunchy melted cheese speckled the surface, while the inside was creamy, savory cubes of bread strewn with sausages and onions, flavored with sage. It reminded me a little of Thanksgiving stuffing, but cheesier — and better with coffee.
Perhaps best of all for our host, it could be assembled entirely before the New Year’s Eve revelries even began. The next morning, while her morning coffee brewed, she simply popped the cold pan into a hot oven. An hour later, it was a bubbly, burnished vision on the table. So easy, filling and especially soothing after a night of copious Champagne-drinking, it made me a breakfast casserole convert from that moment on.
The basic formula is extremely forgiving. As long as you keep the backbone of custard-soaked bread, you can embellish it however you wish: sausages, bacon, vegetables, herbs, different varieties of cheese, you name it.
For this strata, I went meatless, opting for a mix of browned, earthy mushrooms and gently sweet butternut squash. Then, I seasoned it all with sage, which works well with those wintry flavors and added a pinch of red-pepper flakes to mimic a hot Italian sausage-like burn. For the cheese, I used a classic combination of mild, milky mozzarella and sharp Parmesan for lushness and depth.
Breakfast casserole recipes call for a variety of different breads, from feathery brioche to crusty sourdoughs. The lighter the bread, the more puffed and ethereal the casserole; the denser the bread, the heartier and richer. Here, I chose the middle ground: a simple baguette. But feel free to use whatever bread you have, as long as it’s not too seedy, which can interfere with the creaminess.
Assemble it ahead, then bake it as your guests arrive, whether that’s for a holiday breakfast or brunch, or even a cozy dinner. Just rebrand it as a vegetable casserole and serve it as a side dish — or make this gorgeous casserole the star.
Recipe: Mushroom-Butternut Squash Strata
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