Pressure cook mutton pieces with two cups of water, salt and turmeric powder for six whistles. Open the lid when the pressure reduces, drain and reserve the cooking liquor.
Dry roast poppy seeds, fennel seeds, black peppercorns, coriander seeds, cumin seeds, cinnamon, cloves and green cardamoms. Cool and grind to a fine powder. Heat oil in kadai (wok). Add curry leaves and onions. Sauté till the onions are brown. Add ginger-garlic paste, red chilli powder and half the black pepper powder and sauté for a minute.
Add tomato and mutton pieces, cook on high heat till the tomato is soft. Add salt and the spice powder and simmer for five minutes.
Add the reserved cooking liquor and one cup of water and bring to a boil. Simmer till all the mutton pieces get well coated with thick gravy.
Add the remaining black pepper powder and stir well. Garnish with coriander leaves and serve hot.