Heat oil in a pan and saute the onion and all the whole garam masala till the onions turn light brown. Add the tomatoes and continue to fry till it is mashed.
Now add the ginger-garlic paste and all the powdered spices mixed with 1/4 cup water. Saute till the oil separates.
Add the mutton and the curry leaves. Fry on a low flame till dry. Add the chana dal, tamarind paste and 1 & 1 /2 cups water.
Pressure cook for 25 minutes on a low flame after the first whistle. Garnish with coriander leaves, ginger julienne and green chilies. Serve either with rice, plain Biryani, jeera rice, naan or tandoori roti.