Mix together 1 cup of vegetable oil, ½ cups of vinegar, 2 cloves minced garlic, 1 tablespoon salt, and black pepper in a bowl. Add the trimmed lamb leg, coat with the marinade and leave marinating at room temperature for 2 hours.
Meanwhile, stir together the water, lemon juice, 3/4 cup of vegetable oil, tomato puree, onion, 2 tablespoons of vinegar, hot sauce, chilli, 2 cloves minced garlic, mustard powder and 1 teaspoon of salt in a large saucepan. Bring to a boil over medium-high heat, then reduce heat to medium-low, and simmer 30 minutes until the onions have softened and the sauce has thickened.
Preheat the barbecue for medium-low heat, and lightly oil grate.
Remove lamb from marinade, and shake off excess. Discard remaining marinade. Cook 1½ to 2 hours, turning and basting frequently with the hot barbeque sauce.
Used different ingredients.
I stuck to the exact recipe for marinading the lamb but tweaked the bbq sauce as follows: I added 2 finely chopped habanero chilli peppers instead of 1 tsp red chilli. I also added some cherry tomatoes to the sauce and blended it, after it was cooked. - 17 May 2009
Yum, Yum, Yum!!!!! This was absolutely delicious! I served atop a baby spinach salad drizzled with the sauce. Hubby and kids loved it and will make for family bbq!! Both the lamb and the sauce on their own are lovely, combined, even better! - 13 Jan 2010