Autumn Harvest Burger with Butternut Squash and Sage

Name: Autumn Harvest Burger with Butternut Squash and Sage
Prep time: 20 min
Cook time: 25 min
Total time: 45 min
Yield: 4 servings
Cuisine: American
Ingredients: 680 g ground beef (80/20 blend); 150 g butternut squash, peeled and cubed; 30 g butter, divided; 12 fresh sage leaves; 1 large apple (Honeycrisp or Granny Smith), thinly sliced; 30 ml maple syrup; 4 brioche buns, split and toasted; 110 g Gruyère cheese, sliced; 60 g arugula or mixed greens; Salt and pepper, to taste; 30 ml olive oil