We're heading into prime brunch season, which means that brunch casseroles are about to enjoy their heyday. So I decided to revisit one of our most popular recipes ever, published several years ago for a breakfast bake with bread, pancetta, Gruyere, and eggs. I'm afraid I'll sound horribly hyperbolic if I talk about this recipe too long: It's rich, eggy, and unbelievably, incredibly delicious.
This is one to memorize, folks, and to pull out for in-laws and overnight guests. It may just be the very best brunch casserole I've ever made.
I ate a lot of breakfast casseroles growing up. Anytime there was a crowd to be fed before noon, this baked dish of egg, sausage, cheese, and day-old bread would appear. And yet, as an adult, I've discovered that the classic breakfast casserole is a relative mystery to many of our friends.
The appeal is this: You throw everything in the dish the night before, allow the bread to soak up the egg-and-milk mixture overnight, and bake it in the morning. Breakfast casserole is perfect for a brunch party since you don't have to stand at the stove making individual omelettes or batches of pancakes. And it beats waiting outside in the cold at a crowded restaurant.
This recipe is an updated version of the gooey, sausage-and-cheddar casseroles of my youth, and it was inspired by a fancy ham and cheese sandwich. We used pancetta and Gruyère (although you could try an even more sophisticated cheese, with challah bread and caramelized onions for a touch of sweetness). Then we added nutmeg and thyme to brighten things up.
The best part about this make-ahead casserole? You get to sleep in (and even crawl back to bed while it bakes in the oven).
When I revisited this casserole, I did so with great anticipation. It's always received rave reviews and I was hungry to try it. I wasn't disappointed (and neither was my husband, who fell upon it the next morning with a glint of this-is-too-good-to-be-true delight in his eye). This dish is outrageously good, with tender, eggy bread and savory cheese in every bite.
I've made a lot of breakfast casseroles, but this is the first one to be layered in such a distinct way. Usually I jumble the bread, meat, and cheese all up together. This one is baked in layers, like a strata, with the bread on the bottom, then the pancetta, cheese, and herbs. This makes for a beautiful presentation and a very tasty dish; I liked how the layers looked as they were spooned out.
A couple notes: While the make-ahead aspect of this dish is very convenient, you don't have to make it ahead. You can also throw it together and bake it immediately.
Also, I did find that it needed a little more time to bake, especially since I used a deeper oven-safe bowl to bake it in. So that is reflected in changes to the instructions below.
4 cups (loosely packed) day-old challah or other egg-enriched bread, cut into 3/4-inch cubes
2 tablespoons olive oil, divided
1 medium yellow onion, thinly sliced
1/2 teaspoon salt
1/4 teaspoon sugar
1/2 pound pancetta (thickly sliced), diced
6 large eggs
1 1/2 cups whole milk
1/2 teaspoon dry mustard
1/4 teaspoon freshly grated nutmeg
2 teaspoons fresh thyme leaves
Salt and freshly ground black pepper
1 cup grated Gruyère cheese, from about 4 ounces
Grease an 8-inch square baking dish (or another 1 1/2-quart to 2-quart baking dish) and spread the cubed challah in the bottom.
Heat 1 tablespoon of the olive oil in a skillet over medium to low heat. Add the onions, salt, and sugar. Sauté until they are lightly caramelized (a medium golden-brown color), about 15 minutes.
Meanwhile, in another heavy skillet, heat the other tablespoon of olive oil over medium heat and sauté the pancetta until the fat is almost all rendered and it begins to get crisp, about 8 to 10 minutes. Set on a paper towel to drain.
Whisk together the eggs, milk, dry mustard, nutmeg, and thyme. Season with about 1/4 teaspoon of salt and a generous quantity of black pepper.
Spread the pancetta over the bread cubes, then layer the onions on top. Sprinkle grated Gruyère on next, and then pour the egg mixture over the entire thing.
Press down on the top gently, so that all of the bread cubes get soaked a bit with the egg mixture. Cover and refrigerate overnight.
In the morning, take the casserole out of the fridge so it can warm on the counter, and preheat the oven to 350°F. Bake, uncovered, for 35 to 50 minutes, or until the edges are bubbling and the top begins to brown. The baking time will be greatly dependent on the depth of dish you use. Check the interior with a knife; if it comes out clean the bread custard is baked through. (Cover with foil near the end of cooking if the top is already browned.)