Butternut Squash Gratin With Gruyere and Parmesan 1 1/2 pounds butternut squash, peeled and sliced 1/4-inch thick 2 tablespoons olive oil Salt and pepper 3 tablespoons thyme, picked 1 1/2 pounds Yukon Gold potatoes, washed and sliced 1/4-inch thick 1 cup milk 1 cup heavy cream 1/4 cup butter 1 1/2 cups grated gruyere 1 cup Parmesan Join THE FOOD 766 views10:00