Preheat your oven to 375°F (190°C).

Peel and seed the butternut squash, then cut it into 1-inch cubes. Chop the apples into similar-sized pieces.

In a large mixing bowl, toss the cubed butternut squash and chopped apples with olive oil, maple syrup, and a pinch of salt and pepper.

Spread the coated butternut squash and apples on a baking sheet and roast for about 25 to 30 minutes until tender and lightly browned.

Chop fennel and onion, sauté in a skillet with olive oil until golden brown and soft, about 8 minutes.

Add the sweet Italian sausage to the skillet and cook until browned and fully cooked through.

In a large mixing bowl, combine the roasted butternut squash, apples, caramelized fennel, onions, and cooked sausage.

Transfer the mixture into a greased baking dish, top with Gruyere cheese, and bake for an additional 20 minutes until bubbly and golden.