# What you need:
→ Custard Mixture
01 - 3 large eggs
02 - 3/4 cup whole milk
03 - 1/4 cup heavy cream
04 - 1 tablespoon granulated sugar
05 - 1/2 teaspoon kosher salt
06 - 1/2 teaspoon ground black pepper
07 - 1/2 teaspoon Dijon mustard (optional)
→ Bread
08 - 8 slices brioche or challah bread, about 1/2 inch thick
→ Cheese Filling
09 - 8 slices Gruyère or sharp cheddar cheese, or a combination
→ For Cooking
10 - 2 tablespoons unsalted butter
11 - 1 tablespoon neutral oil (such as canola)
# How to Make It:
01 - Whisk together eggs, whole milk, heavy cream, sugar, kosher salt, black pepper, and Dijon mustard in a shallow bowl until fully combined.
02 - Arrange 4 slices of bread on a work surface, top each with 2 slices of cheese, then cover with remaining bread slices to form sandwiches.
03 - Warm a large nonstick skillet or griddle over medium heat. Add 1 tablespoon butter and 1/2 tablespoon oil, swirling to coat the surface evenly.
04 - Immerse each sandwich in the custard mixture, coating both sides thoroughly without soaking through.
05 - Place custard-coated sandwiches in the skillet. Cook 3 to 4 minutes per side, pressing gently, until golden brown and cheese is melted. Repeat batches as necessary, replenishing butter and oil.
06 - Transfer sandwiches to a cutting board, let rest for 2 minutes, then slice and serve warm.