In a thick sauces pan, melt 2 tablespoons of ghee. Add lamb cubes seasoned with salt and pepper. Brown the lamb. Remove and keep warm.
Saute the onions, garlic, ginger, chillies and tomatoes in remaining ghee for 6-8 minutes.
Stir the lamb and pumpkin. Cook for 25 minutes stirring occasionally to keep from burning.
Pour on water, cover and cook for 40 minutes or until the lamb is tender and the pumpkin turns into a puree.
Season to taste and serve with irio, ugali or ndizi