Potato and Winter Squash Gratin

Name: Potato and Winter Squash Gratin
Ingredients: 2 cups (16 fl. oz./500 ml) heavy cream; 3 cups (12 oz./375 g) shredded Gruyère cheese; 4 garlic cloves, chopped; Kosher salt and freshly ground pepper; 2 Tbs. unsalted butter; 1 lb. (500 g) yellow potatoes, such as Yukon Gold or Yellow Finn, peeled and cut into 1-inch (2.5 cm) cubes; 1 butternut squash, about 2 lb. (1 kg), peeled, halved, seeded and cut into 1-inch (2.5 cm) cubes; 1 acorn squash, peeled, halved, seeded and cut into 1-inch (2.5 cm) cubes