Ingredients:

  • 1 Tablespoon Unsalted Butter
  • 1 Pound Breakfast Sausage (bulk or links, casings removed)
  • 1/2 Medium Yellow Onion, finely diced
  • 1/4 teaspoon Kosher Salt (for seasoning the sausage)
  • 6 cups Brioche or Day-Old French Bread, cubed (1-inch pieces)
  • 2 cups Sharp Cheddar Cheese, freshly grated, divided
  • 8 Large Eggs, lightly whisked
  • 1 1/2 cups Whole Milk
  • 1/2 cup Heavy Cream
  • 1 teaspoon Dijon Mustard
  • 1 teaspoon Kosher Salt
  • 1/2 teaspoon Freshly Ground Black Pepper
  • Pinch Freshly Grated Nutmeg

Instructions:

  1. Preparation: Thoroughly grease a 9x13 inch baking dish. Cube the bread into 1-inch pieces and grate the cheese.
  2. Sauté the Sausage Base: Melt the butter in a large skillet over medium-high heat. Add the sausage and break it up. Cook until browned (5–7 minutes).
  3. Add Aromatics: Add the diced onion to the sausage mixture and cook until softened (about 3 minutes). Drain off any excess grease and set aside to cool slightly.
  4. Layer the Bread: Spread the cubed bread evenly across the bottom of the prepared baking dish.
  5. Layer Sausage and Cheese: Sprinkle the cooked sausage and onion mixture over the bread. Top this layer with 1 1/2 cups of the grated cheddar cheese.
  6. Whisk the Custard: In a large mixing bowl, whisk together the eggs, whole milk, heavy cream, Dijon mustard, salt, pepper, and nutmeg until fully combined and slightly frothy.
  7. Pour and Soak: Slowly and evenly pour the entire custard mixture over the layers, ensuring all the bread cubes are saturated. Press down gently to aid absorption. Cover tightly and refrigerate for a minimum of 4 hours, or ideally overnight (8–12 hours).
  8. Preheat and Initial Bake: Preheat the oven to 350°F (175°C). Remove the casserole from the refrigerator and let it sit at room temperature for 15 minutes. Remove the plastic wrap and bake for 30 minutes.
  9. Add Final Cheese: Remove the casserole from the oven and sprinkle the remaining 1/2 cup of cheddar cheese over the top.
  10. Final Bake: Return to the oven and bake for another 15–20 minutes, or until the top is golden brown and a knife inserted near the center comes out clean.
  11. Rest: Let the casserole rest uncovered for 10 minutes before slicing and serving. This allows the custard to set fully.