6 ounces thinly-sliced deli ham, torn into quarters
4 whole-wheat English muffins, split, toasted and halved
1/2 cup sundried tomatoes not in oil (about 14), sliced
4 scallions, trimmed and cut into 2-inch pieces
2/3 cup shredded extra-sharp Cheddar, divided
4 large eggs
3 large egg whites
3 cups reduced-fat milk (2 percent)
1 tablespoon Dijon mustard
Kosher salt and freshly ground black pepper
Cooking spray should be lightly misted into a round 2-quart casserole dish. To create a shingled design, alternately arrange the ham and muffins in the dish. Over the dish, strew the sundried tomatoes, scallions, and 1/3 cup cheddar.
Mix the milk, egg whites, mustard, and eggs in a big bowl. Add salt and pepper. Add the remaining 1/3 cup cheese after spreading the custard filling over the casserole. Wrap the casserole in plastic and place it in the fridge for at least 5 hours or even overnight.
Set the oven to 350 degrees Fahrenheit. Place the casserole on a large rimmed baking sheet, and bake for approximately an hour, or until the rims are golden and the center is just set. 10 minutes should pass before serving.