LAMB AND SEASONING: Place racks in middle and bottom positions in oven; preheat oven to 450. Place lamb on rack in large roasting pan. Combine oil, rosemary, garlic, salt and pepper; rub paste over lamb. Roast on middle oven rack 15 minutes. COMPOTE: Meanwhile, in medium roasting pan, combine tomatoes, onion, 2 tablespoons if the oil, the garlic, and pepper; place on bottom oven rack. Reduce temperature to 350. Roast lamb and tomato mixture, roasting lamb pan and stirring tomatoes once, 1.5 hours or until internal temperature of thickest part of lamb registers 145 on instant-read thermometer for medium-rare (shank end will be medium). Transfer lamb to cutting board; tent loosely with foil; let stand 15 minutes; carve. Into tomato mixture, stir remaining oil, the olives, sugar, vinegar and capers. Serve with the lamb. Makes 8 servings.