In a bowl, combine olive oil, minced garlic, chopped rosemary, salt, and black pepper. Rub this mixture all over the leg of lamb. Cover and let marinate in the refrigerator for at least 2 hours or overnight for best results.

Roast the Lamb

Preheat the oven to 375°F (190°C). Place the marinated leg of lamb on a roasting rack in a roasting pan. Roast for about 1.5 to 2 hours, or until the internal temperature reaches 135°F (57°C) for medium-rare. Let it rest for 15 minutes before slicing.

Tamarind Sauce Preparation

Make the Sauce

In a saucepan, combine tamarind paste, brown sugar, soy sauce, water, and grated ginger. Bring to a simmer over medium heat and cook for 10 minutes, stirring occasionally. Remove from heat and set aside.

Fava Bean Risotto Preparation

Prepare the Risotto

In a large skillet, melt butter over medium heat. Add chopped onion and minced garlic, cooking until translucent. Add Arborio rice and cook for 2 minutes, stirring constantly. Gradually add vegetable broth, one ladle at a time, stirring often until the liquid is absorbed before adding more. After about 15 minutes, add the shelled fava beans and continue cooking until rice is creamy and al dente.

Finish the Risotto

Stir in grated Parmesan cheese, chopped mint, and season with salt and black pepper to taste. Remove from heat.