Preheat the oven to 375 degrees. Butter a gratin dish, and arrange layers of potatoes, then turnips and then rutabagas, seasoning between each layer with salt and pepper, and continuing until you reach the top of the gratin dish. Heat the cream with the sage leaves, and pour over vegetables. Cover with grated cheese and bake for 40-50 minutes, until vegetables are softened. Test with a skewer for doneness.

Turnip Tureens

Select large turnips, and carve out the center. Blanch in simmering water until almost completely cooked, turn upside down to drain and cool. Fill with mashed potatoes and turnips or creamed turnip tops or spinach. Serve right away, or top with grated cheese and broil. These look pretty when served on bed of turnip greens.