Total Time: 1 hour
RECIPE OVERVIEW A café breakfast sandwich is all about the eggs. Combining eggs, milk, and salt and baking the mixture in an 8-inch pan produces the perfect pillowy egg layer. Covering the pan with aluminum foil while baking delicately cooks the eggs. We cut the cooked egg sheet into four perfect squares that can be eaten right away or stored in the fridge for another morning. We add sliced ham and shredded Gruyère to the egg squares and pop them back in the oven to heat through and melt. Baby arugula provides freshness, while Dijon mayonnaise adds richness and a hint of spice. Potato, kaiser, and brioche buns measuring roughly 4 inches in diameter all work well here.
8 large eggs
½ cup milk
½ teaspoon table salt
3 tablespoons mayonnaise
1 tablespoon Dijon mustard
4 slices deli ham
4 ounces Gruyère cheese, shredded (1 cup)
4 hamburger buns, toasted
1 ounce (1 cup) baby arugula
1. Adjust oven rack to middle position and heat oven to 300 degrees. Generously spray bottom and sides of 8-inch square baking pan with vegetable oil spray. Whisk eggs, milk, and salt in bowl until well combined. Transfer egg mixture to prepared pan; cover tightly with aluminum foil; and bake until egg is set, 30 to 35 minutes, rotating pan halfway through baking.
2. Run thin knife between egg and side of pan. Invert egg onto cutting board and cut into four squares. Combine mayonnaise and mustard in small bowl. (Egg squares and mayonnaise-mustard mixture can be refrigerated separately for up to 3 days. To reheat egg squares, increase baking time in step 3 to 4 to 6 minutes.)
3. Arrange egg squares on greased rimmed baking sheet and top each square with 1 slice ham and ¼ cup Gruyère. Bake until ham is heated through and Gruyère is melted, 2 to 4 minutes.
4. Spread 1 tablespoon mayonnaise-mustard mixture on each bun top. Place egg squares on bun bottoms and top each with ¼ cup arugula and bun tops. Serve.