CHEESY KALE BREAKFAST CASSEROLE

Cheesy Kale Breakfast Casserole image

Provided by Molly Yeh

Time 1h20m

Yield 8 servings

Number Of Ingredients 15

2 tablespoons unsalted butter
1 yellow onion, diced
16 ounces crusty sourdough, cut into cubes
1 cup shredded mozzarella (about 4 ounces)
1 cup shredded Gruyere or Swiss (about 4 ounces), plus more for topping
6 ounces kale, chopped (chard or spinach would always work!)
3 1/2 cups whole milk
1/2 cup heavy cream
2 teaspoons Dijon mustard
1 1/2 teaspoons kosher salt
1/4 teaspoon grated nutmeg
8 large eggs
4 sprigs fresh thyme, leaves only
A few shakes hot sauce
Freshly ground black pepper

Steps:

If you're planning to bake this immediately, preheat the oven to 350 degrees F. If you're prepping this the day before, no need to preheat now.
In a skillet (or 4-quart braiser that you can put in the oven), heat the butter over medium heat. Add the onion and cook until softened, 5 to 7 minutes.
Combine the sourdough, mozzarella, Gruyere and kale with the buttery onion mixture, either in a 9-by-13-inch casserole dish or in the braiser.
In a large bowl, whisk together the milk, cream, mustard, salt, nutmeg, eggs, thyme, hot sauce and a bunch of turns of pepper. Pour into the casserole dish over the bread mixture. Top with another little sprinkle of Gruyere. Cover with foil and bake immediately or refrigerate up to 24 hours.
Bake, covered, for 30 minutes. Remove the foil and continue to bake until browned on top and set throughout, about another 30 minutes.