Ingredients:

  • 8 cups stale bread, cubed (approx. 1 standard loaf)
  • 1 pound bulk breakfast sausage
  • 1/2 cup yellow onion, finely chopped
  • 2 cups sharp cheddar cheese, grated (divided)
  • 10 large eggs
  • 2 cups whole milk
  • 1 teaspoon Dijon mustard
  • 1/2 teaspoon dried thyme
  • 1 teaspoon salt (adjust based on sausage)
  • 1/2 teaspoon black pepper
  • Butter or cooking spray for greasing

Instructions:

  1. Cube the bread into 1-inch pieces. If the bread is fresh, spread cubes on a baking sheet and toast lightly in a 300°F (150°C) oven for 10 minutes to dry them out slightly. Set aside.
  2. In a large skillet, brown the sausage, breaking it up as you go. Drain off all but 1 tablespoon of the rendered fat. Add the onion and sauté until softened (about 4 minutes). Remove from heat.
  3. In a 9x13 inch baking dish, combine the toasted bread cubes, the cooked sausage/onion mixture, and 1.5 cups of the grated cheddar cheese. Toss gently to distribute evenly.
  4. In a large bowl, vigorously whisk the eggs, milk, Dijon mustard, thyme, salt, and pepper until completely homogenous and slightly frothy.
  5. Slowly pour the custard evenly over the bread mixture in the baking dish. Gently press down on the bread with the back of a spatula to ensure all pieces are soaking up the liquid. Cover and refrigerate for at least 30 minutes, or preferably overnight.
  6. Preheat your oven to 375°F (190°C). Remove the casserole from the fridge about 20 minutes before baking to take the chill off. Sprinkle the remaining 0.5 cup of cheddar cheese over the top.
  7. Bake uncovered for 45–50 minutes, or until the casserole is puffed, golden brown on top, and a knife inserted near the centre comes out clean.
  8. Let the casserole rest for 10 minutes before slicing and serving.