Bangladeshi Lamb with Rice

Name: Bangladeshi Lamb with Rice
Ingredients: 1 kilogram lamb – cut into medium sized pieces; 2 large onions; 175 grams unsalted butter; 4 medium cinnamon sticks; 10 green cardamons; 1 heaped tablespoon whole black peppercorns; 10 cloves; 0.5 tablespoon cumin seeds; 3 black cardamons; Pinch of grated nutmeg; Pinch of ground mace; 5 teaspoons coriander-cumin powder; 1 teaspoon turmeric powder; 2 teaspoons chilli powder; 375 grams natural yoghurt (not greek style, not fat-free); 150 millilitres kewra water; 3 cloves garlic – peeled and finely chopped; 35 grams root ginger – peeled and finely chopped; 1 gram saffron; 2 tablespoons light tasting vegetable oil; 20 baby potatoes – washed; 500 grams pitted prunes; 8 green chillies – washed; 300 grams rice; 1.5 tablespoons salt