1/2 stick (1/4 cup) unsalted butter, softened, plus additional for greasing baking dish
1 (1-lb) package bulk breakfast sausage (not links)
8-x4-inch sized loaf crusty bread (I used French mini baguettes)
1 garlic clove, chopped
24 large eggs
1 cup whole milk (or 2%)
2 teaspoons salt
1 teaspoon black pepper
2 teaspoons Dijon mustard
1 large bunch scallions, chopped (1 1/4 cups)
1/4 lb sharp Cheddar, coarsely grated (1 cup)