Stewed Lamb in Dark Almond Sauce

2 pounds boneless lamb shoulder or other lamb for stew, trimmed of fat
6 tablespoons vegetable oil
10 cloves
1 to 2 whole dried hot red peppers (optional)
12 black peppercorns
6 whole cardamom pods
6 garlic cloves
1-inch cube fresh ginger
3 tablespoons blanched almonds
1 tablespoon ground cumin
2 tablespoons ground coriander
1 tablespoon shredded coconut
1/2 teaspoon ground turmeric
1/8 teaspoon ground nutmeg
1/4 teaspoon ground mace
2 medium onions
3 tablespoons yogurt
3 medium tomatoes, peeled
Salt to taste

Cut the meat into 1-inch cubes and dry well with paper towels.
Heat the oil in a large frying pan. When hot, add the cloves, red peppers, peppercorns, and whole cardamom pods. Stir for a few seconds until the cardamom pods puff up and darken.
Now brown the meat in the pan, 7 or 8 pieces at a time, turning to color them on all sides. Transfer the meat to a large flameproof casserole with a slotted spoon, leaving the spices in the frying pan. Brown all the meat in this way, then cover the casserole and set aside.
Peel and coarsely chop the garlic and ginger; set aside. Roughly chop the almonds.
Heat a small cast-iron frying pan. Add the cumin, coriander, coconut, and almonds and dry-roast over medium heat, stirring, for about 5 minutes or until the spices turn a coffee color. Transfer the roasted spices and nuts to a blender. Add the chopped garlic and ginger.
With a slotted spoon, lift out the fried spices from the frying pan and add these to the blender too. Add the turmeric, nutmeg, mace, and 8 tablespoons water. Blend to a smooth, thick paste.
Saute diced onion in lamb pan juices to tender; add in paste from blender and stir to incorporate over medium heat. Gradually add in yogurt while stirring; add chopped tomatoes, ~1 cup water or broth, cover and and simmer for 15 minutes; add meat and simmer gently for about an hour. Season with salt and pepper to taste.

Could easily adapt to slow cooker.