Roast Leg of Lamb Provençal

• 1 leg of lamb (about 6 pounds)
• 1 tablespoon butter

Have your butcher trim and tie a leg of lamb. Butter a shallow fire-proof casserole or gratin dish just large enough to hold leg of lamb comfortably and rub it lightly with a cut clove of garlic. Peel and cut potatoes in thick slices and arrange in the bottom of the dish in overlapping rows. Salt and pepper the potatoes generously. Chop remaining garlic finely and sprinkle over potatoes with fi