Grind chili peppers, mustard seeds, cumin seeds, peppercorns, cardamom seeds, and cinnamon in a coffee- grinder or other type of grinder. Put the spices in a bowl, add the salt, vinegar, and sugar. Mix well and set aside. In a wide heavy pot over medium heat, heat the oil. Add onions and fry
, stirring often until they turn crisp and brown
. Remove the onions (and turn off heat) with a slotted spoon and place in a blender along with 2 or 3 tablespoons of water. Puree
the onions. Add the puree to the bowl with the ground spices. You've just made vindaloo paste! Put the ginger and garlic into the blender, along with 2 or 3 tablespoons of water. Blend until this becomes a smooth paste. Heat oil in the pot again over medium high heat. When hot, add the lamb cubes, a few at a time, turning to brown on all sides. Remove each batch with a slotted spoon and place in a large bowl. Add the ginger-garlic paste to the pot and turn down the heat to medium. Stir for a few seconds. Add the tumeric and coriander, stirring. Add the meat, along with any accumulated juices and the vindaloo paste and 1 cup of water. Bring to a boil. Cover and simmer
for about 1 hour or until the lamb is tender, stirring occasionally. Makes 6 servings.