Kielbasa, Apple, and Onion Strata with Mornay Sauce

Preheat the oven to 350F and lightly butter a 2-quart baking dish or cast-iron skillet.

将鸡蛋，牛奶，芥末，盐和肉豆蔻一起搅拌在一个大碗中。使用刮刀，小心地折叠在干燥的面包中，使其浸泡液体的大部分。留出至少15分钟。

In a large skillet, melt 1 tablespoon of butter over medium heat. Add the kielbasa and cook, turning once, until browned on both sides, about 3 minutes. Transfer the kielbasa to a cutting board, but keep all of the butter and kielbasa fat in the pan. Reduce the heat to low, add the onions and cook, stirring occasionally until tender but not browned, about 5 minutes. Add the apples and cook until softened, about 3 minutes. Season lightly with salt and allow the mixture to cool a bit. Once the sausage is cooled, slice it into 1/2-inch rounds.

Add the cooled apple mixture, kielbasa, and Gouda to the soaked bread and fold together with a spatula until evenly combined. Transfer to the prepared baking dish or pan and bake until golden brown and a skewer inserted in the center comes out clean, 35 to 45 minutes. (Alternately, let the uncooked mixture rest overnight and bake it the next day straight out of the fridge, adding about 10 minutes to the baking time).

Meanwhile, make the Mornay sauce: In a small saucepan, melt the butter over medium-low heat. Whisk in the flour to make a paste and continue cooking and whisking until golden brown, about 1 minute. Whisk in the milk in a steady stream, continuing to whisk until sauce is smooth. Bring to simmer, reduce the heat to low, and cook, whisking often, until sauce is thick and smooth, about 8 minutes. Mix in the cheese, season with salt and a pinch of nutmeg, and heat until cheese is just melted and sauce is smooth.

用Mornay酱，毛毛雨的蜂蜜，撒上淋浴，撒上片状海盐的楔子。