Raita is a fresh yogurt sauce that typically accompanies curries and other Indian dishes. This raita also acts as a marinade.
15-pound leg of lamb, boned, butterflied, well trimmed
1/2 cucumber, peeled, seeded, diced
With machine running, drop garlic, jalapeño and ginger through the feed tube and process until finely chopped, scraping down sides occasionally. Add cilantro and mint and process until finely chopped. transfer mixture to medium bowl. Add yogurt and blend well. Season to taste with salt and pepper.
Arrange lamb in 13x9x2-inch glass baking dish. Spread half of yogurt mixture over lamb, covering completely. Cover lamb and let stand at room temperature 2 hours or cover and refrigerate overnight. Cover remaining yogurt mixture and refrigerate.
Preheat oven to 375°F. Arrange lamb on baking sheet. Bake until thermometer inserted into thickest part registers 140°F., about 50 minutes. Transfer to platter and let stand 10 minutes.
Meanwhile, add cucumber to remaining yogurt mixture. Cut lamb crosswise into thin slices. Serve, passing yogurt mixture separately.