Whaaaaaaaaaaaaaat?! No, I haven’t made it, yes, I’m going to for a Christmas family visit.
Just in case you are as in love with Croque Monsieur as I am and need a casserole for the holiday season, here ya go:
Butter, for coating the baking dish
2 cups whole milk
7 large eggs
3/4 teaspoon freshly ground black pepper
1/4 teaspoon kosher salt
4 teaspoons Dijon mustard
12 ounces day-old crusty bread, cut into 10 (1/2-inch-thick) slices
1/4 cup chopped fresh chives
12 ounces thinly sliced ham
2 cups grated Gruyère cheese, divided
1 to 2 cups arugula
1 medium lemon, juiced
1 teaspoon olive oil
Generously coat a 9×13-inch baking dish with butter and set aside. Whisk the milk, eggs, pepper, and salt together in a large bowl. Spread the mustard on one side of each slice of bread. Place half of the bread slices Dijon-side up in the baking dish.
Spoon half of the egg mixture over the bread, making sure that each piece is fully covered. Sprinkle the chives over the bread and egg mixture. Place the ham slices over the bread in an even layer. Sprinkle with half of the Gruyère cheese. Layer with the remaining bread Dijon-side down. Pour over the remaining egg mixture. Sprinkle with the remaining cheese. Cover and refrigerate at least 30 minutes or overnight.
Arrange a rack in the middle of the oven and heat 350°F. Bake uncovered until the egg mixture is set and cheese is bubbly and lightly browned, 35 to 40 minutes. Let stand for 5 minutes.
Meanwhile, toss together the arugula, lemon juice, and olive oil in a small bowl and spread over the casserole immediately before serving.
- Storage: Leftovers can be stored in an airtight container in the refrigerator for up to 3 days.