Preheat oven to 350°F (175°C) and butter a 9x13-inch baking dish.

In a large skillet, heat olive oil over medium heat. Add sausage, breaking it apart as it cooks for about 5-7 minutes until browned. Transfer to a bowl.

Using the same skillet, add more olive oil if needed and sauté leeks, onion, and fennel for 8-10 minutes until tender and lightly caramelized.

Stir in diced apple, sage, and rosemary, continue to cook for 4-5 minutes until apples soften.

Deglaze the skillet with white wine, simmer for 1-2 minutes, then mix in reserved sausage and turn off heat.

In a mixing bowl, combine torn bread with sausage and vegetable mixture. Incorporate 2 cups of stock and let it sit for 10 minutes.

Whisk eggs with any remaining stock and pour over the bread mixture, stirring to coat evenly.

Transfer mixture to the prepared dish, cover with foil, and bake for 30 minutes. Remove foil and bake for another 30 minutes until golden brown.

Let the stuffing rest for 10 minutes before serving to allow flavors to settle.