Croissant Breakfast Casserole for Day-Old Croissants

Ingredients

• 6 day-old butter croissants, torn (420 g)
• 8 large eggs (400 g)
• 1 1/2 cups whole milk (360 g)
• 1/2 cup heavy cream (120 g)
• 8 ounces cooked ham, diced (225 g)
• 2 cups baby spinach (60 g)
• 1 1/2 cups shredded Gruyere (170 g)
• 4 scallions, divided (60 g)
• 1 tablespoon Dijon mustard (15 g)
• 1 teaspoon fine salt (6 g)
• 1/2 teaspoon black pepper (1 g)
• 1 tablespoon unsalted butter for the dish (14 g)

Instructions

1. Prepare. Tear the croissants into broad pieces rather than small cubes. Dry the spinach in a skillet with the scallion whites, then cool it briefly. Grease a 9-by-13-inch ceramic baker. Arrange half the croissants loosely, tuck in the ham, spinach and half the Gruyere, then add the remaining croissants and cheese. Keep several flaky tips above the filling.
2. Assemble. Whisk eggs, milk, cream, Dijon, salt and pepper until uniform. Pour the custard slowly across the dish. Press the croissants once and release them; do not flatten their layers. Let the assembled casserole stand for 25 minutes. At the checkpoint, the lower folds should be hydrated while several upper tips remain dry enough to brown.
3. Cook or chill. Bake uncovered at 350°F (175°C) for 35 to 40 minutes. Rotate the dish once if the back edge colors faster. The casserole is ready when the exposed croissant tips are deep gold, the center carries one gentle movement when nudged, and a knife inserted between two center pieces shows moist crumbs without flowing egg.
4. Finish. Let the casserole settle for 10 minutes before cutting eight rectangles. Use a serrated knife through the flaky top, then slide a broad spatula beneath each portion. Finish with the scallion greens. A good slice keeps recognizable croissant folds around the ham and spinach instead of compressing into one dense bread layer.

Notes

• Use the white 9-by-13-inch ceramic baker and preserve the weights. Center cue: the baked casserole with browned croissant peaks and a gently set center that carries one soft movement.
• Refrigerate for up to 4 days. Reheat one portion for 60 seconds, check the center and add brief bursts if needed.

Nutrition Facts