Ingredients:

  • 1 pound (450g) breakfast sausage, removed from casings
  • 1 medium yellow onion, finely diced (about 1 cup)
  • 6 large eggs
  • 1 1/2 cups (355ml) whole milk
  • 1 teaspoon Dijon mustard
  • 1/2 teaspoon salt
  • 1/4 teaspoon black pepper
  • 8 ounces (225g) sharp cheddar cheese, shredded (about 2 cups)
  • 1/4 cup (15g) fresh chives, finely chopped
  • 6 slices of bread (such as white, whole wheat or brioche), cut into 1-inch cubes (about 4 cups)
  • 1 tablespoon unsalted butter, softened (or cooking spray)

Instructions:

  1. Brown the sausage in a large skillet over medium heat, breaking it up with a spoon. Add the diced onion and cook until softened, about 5 minutes. Drain any excess grease.
  2. In a large mixing bowl, whisk together the eggs, milk, Dijon mustard, salt, and pepper until well combined.
  3. Grease a 9x13 inch baking dish with butter or cooking spray. Arrange the bread cubes in a single layer at the bottom of the dish. Sprinkle the cooked sausage and onion mixture evenly over the bread. Top with shredded cheddar cheese and chopped chives.
  4. Pour the egg mixture evenly over the sausage, cheese, and bread, making sure to saturate all the ingredients. Gently press down with a spatula to ensure the bread absorbs the mixture.
  5. Cover the casserole with plastic wrap and refrigerate for at least 30 minutes, or up to overnight. This allows the flavors to meld together and the bread to absorb the egg mixture.
  6. Preheat oven to 350°F (175°C). Uncover the casserole and bake for 45-55 minutes, or until the eggs are set and the top is golden brown. A knife inserted into the center should come out clean.
  7. Let the casserole cool for 10-15 minutes before slicing and serving.