Ingredients:

  • 500 g (1 lb) Sourdough or rustic artisan bread, cut into 1-inch cubes
  • 30 g (2 tbsp) Unsalted butter, divided
  • 450 g (1 lb) Sage or good quality breakfast sausage (casings removed)
  • 1 Large yellow onion, finely diced
  • 100 g (4 oz) Fresh spinach, roughly chopped
  • 2 Cloves garlic, minced
  • 5 ml (1 tsp) Dried thyme
  • Salt and freshly ground black pepper, to taste
  • 8 Large eggs
  • 500 ml (2 cups) Whole milk
  • 120 ml (½ cup) Heavy cream (or double cream)
  • 15 ml (1 tbsp) Dijon mustard
  • 5 ml (1 tsp) Worcestershire sauce
  • 5 ml (½ tsp) Grated nutmeg
  • 225 g (8 oz) Gruyère cheese, grated (about 2 cups)
  • 50 g (½ cup) Parmesan cheese, finely grated (for topping)

Instructions:

  1. Toast the Bread (Optional but recommended): Preheat oven to 350°F (175°C). Spread bread cubes on a sheet pan and bake for 8-10 minutes until slightly crisp but not colored. Set aside.
  2. Sauté the Meat: Melt 1 tbsp of butter in a large skillet over medium-high heat. Add the sausage meat, break it apart, and cook until browned. Drain off any excess fat and set the sausage aside.
  3. Caramelise and Finish the Filling: Reduce heat to medium. Add the remaining 1 tbsp of butter, diced onion, and a pinch of salt to the skillet. Cook gently for 6–8 minutes until the onions are soft. Add the minced garlic and thyme; cook for 1 minute. Stir in the chopped spinach just until wilted. Remove the pan from the heat and stir the cooked sausage back into the vegetable mixture.
  4. Make the Custard: In a large mixing bowl, whisk together the eggs, whole milk, heavy cream, Dijon mustard, Worcestershire sauce, nutmeg, salt, and pepper until fully combined and slightly frothy.
  5. Layer and Soak: Grease a 9x13 inch casserole dish. Spread half of the toasted bread cubes evenly across the bottom. Scatter the entire sausage and vegetable mixture over the bread. Sprinkle half (1 cup) of the Gruyère cheese over the filling. Place the remaining bread cubes on top. Evenly pour the egg custard mixture over the entire casserole.
  6. Press and Chill: Gently press the bread cubes down with a spatula to ensure maximum liquid absorption. Cover the dish tightly with cling film and chill for a minimum of 4 hours, or ideally, overnight (this soaking period is essential).
  7. Bake (Covered): Preheat the oven to 375°F (190°C). Remove the casserole from the fridge. Sprinkle the remaining 1 cup of Gruyère cheese and the grated Parmesan evenly over the top. Bake the casserole, covered loosely with foil, for 30 minutes.
  8. Final Bake (Uncovered) and Rest: Remove the foil and continue baking for 20–25 minutes, or until the top is deeply golden brown and a knife inserted near the center comes out clean. Remove from the oven and let it rest for 10 minutes before slicing and serving.