How to Make It
Soak six 10-inch bamboo skewers in warm water for 30 minutes. Meanwhile, in a medium shallow glass baking dish, sprinkle the lamb with 1 tablespoon of the coriander, the salt and 1 1/2 teaspoons of the pepper. Add 1 1/2 tablespoons of oil and toss to coat. Let marinate for 30 minutes.
In a medium saucepan, combine the tamarind, sugar, sweet soy sauce, garlic and the remaining 1/2 tablespoon of coriander and 3/4 teaspoon of pepper. Bring to a boil, then simmer over moderate heat for 5 minutes. Let cool.
In a deep skillet, heat 1 cup of oil until shimmering. Add the shallots and fry over moderate heat, stirring, until golden and crisp, 4 minutes. With a slotted spoon, transfer to paper towels.
Light a grill. Lightly oil the grate. Thread the lamb onto the skewers. Set aside half of the barbecue sauce for serving. Grill the lamb over a medium-hot fire for 8 minutes, turning once and basting often with the tamarind sauce for medium-rare meat. Transfer the skewers to plates, sprinkle with the shallots and serve with the remaining sauce.