2 pounds turnips, peeled and sliced in thin rounds
Salt and freshly ground pepper
4 ounces Gruyère cheese, grated (about 1 cup tightly packed)
2 1/2 cups low-fat milk (1 percent or 2 percent)
1 teaspoon fresh thyme leaves, roughly chopped
Preheat the oven to 400 degrees
Butter or oil a 2-quart baking dish or gratin dish.
Rub the sides and bottom with the cut clove of garlic
Place the sliced turnips in a bowl and season generously with salt and pepper
Add half the cheese and the thyme and toss together, then transfer to the gratin dish and pour on the milk. It should just cover the turnips
Place in the oven and bake 30 minutes
Push the turnips down into the milk with the back of a large spoon
Sprinkle the remaining cheese over the top and return to the oven
Bake another 40 to 50 minutes, until all of the milk is absorbed, the turnips are soft and the dish is nicely browned on top and around the edges
Let it sit for 20 to 30 minutes after baking, so the turnips will reabsorb the moisture from using lower-fat milk. You can assemble this several hours before baking, but don’t add the milk until you’re ready to bake.