Rebekah's Coconut Curry Lamb

13-4lb lamb roast or 2-3 pounds lamb stew meat
salt and fresh ground black pepper to taste
3 Tbsp lard or other fat
3 med onions, sliced into wedges
2 tsp turmeric
5 med boiling potatoes, peeled and quartered
1 4oz can curry paste of your choice
2 14oz cans unsweetened coconut milk
1 1/2 C water
Preheat oven to 300 degrees.  Bring the lamb to room temp.  Trim the roast of any excess fat, and sprinkle with salt and pepper.  Heat the fat in a large, flameproof casserole over medium heat.  Brown the roast on all sides, about 3 min per side; remove and set aside.
Toss the onions into the oil and saute until translucent; sprinkle onions with turmeric, and saute 1 min longer.  Turn the heat to low. Add the potatoes, and stir in the curry paste, coconut milk, and water.  Mix until well blended.
Set the lamb on top, cover tightly, and roast in the oven for 3-4 hours, or until the meat is fork tender. 
Serve over a bed of rice topped with the potato-curry sauce.