Cheesy Root Vegetable Gratin
Ingredients:1-2 long sweet potatoes (about 2 inches thick), peeled4 large parsnips, ends trimmed and peeled5 medium beets, peeled2 1/4 cups heavy cream, divided (whole milk is fine, but mixture wont thicken as much or be as creamy)4 ounces grated Parmesan, divided1 tablespoon fresh minced thyme, divided, plus more for garnish1 garlic clove, minced2 ounces shredded…