Mushroom Pain Perdu - cooking recipe

Ingredients

3 tablespoons unsalted butter, plus more for the cooker
1 (10 ounce) package sliced mushrooms
1 small onion, finely chopped
salt
fresh ground pepper
5 large eggs
2 cups whole milk
1/2 cup freshly grated parmigiano-reggiano cheese
1/4 teaspoon freshly grated nutmeg
6 cups day-old French bread cubes, lightly toasted, 1-inch cubes
1/2 cup grated gruyere cheese or 1/2 cup emmenthaler cheese

Preparation

Butter the insert of a large slow cooker.
In a large skillet, melt the 3 T butter over medium heat.
Add the mushrooms and onion and cook, stirring often, until the mushrooms juices evaporate and the mushrooms are golden, about 10 minutes.
Season to taste with salt and pepper.
In a large bowl, beat the eggs until blended.
Beat in the milk, Parmesan, nutmeg, 1/2 teaspoon salt, and pepper to taste.
Stir in the mushrooms.
Place the bread cubes in a large bowl.
Pour the mixture over the bread cubes and stir well.
Scrape the mixture into the slow cooker.
Press the bread cubes down into the liquid.
Sprinkle with the Gruyere.
Cover and cook on HIGH for 1 1/2 to 2 hours, or until a knife inserted in the center comes out clean.
Serve hot, scooping it out of the dish.