Put the marinade ingredients into a blender and grind them until you get a smooth paste.
Put the mutton, goat meat, into a large non-metallic bowl and pour the marinade over the meat. Mix to coat the meat well.
Place plastic wrap tightly over the bowl and set it in the refrigerator to marinate while you make the gravy.
Heat the cooking oil in a heavy-bottomed pan on medium heat.
When the cooking oil is hot, add the chopped onions. Saute until the onions begin to turn a pale, golden brown.
Add the garlic and ginger pastes and saute the mixture for one minute.
Add the tomato paste, the IWP's powdered spices, special IWP meat masala, and salt to taste. Mix well.
Saute the resulting masala—the onion-tomato-spice mixture—until the oil begins to separate from it (about 10 minutes).
When the masala begins to look ready, turn off the heat.
Put the prepared masala into a blender and grind it into a smooth paste in a food processor.
*Note: Do not add water when blending. Once done, remove the paste and place it in a separate container.
Turn the burner on medium that you used previously to fry the masala.
When the pan is very hot, add the meat and marinade and saute until the meat begins to turn opaque.
Add the masala that you prepared previously and 1/4 cup of boiling water. Stir well.
Cook until the meat is tender and turn off the heat. Keep checking as the meat cooks. Add a little water if needed.
The result should be a dish with thick, minimal gravy.
If liquid remains in the pan when the meat is cooked, cook for a few more minutes, checking frequently.
Garnish the dish with chopped coriander
Enjoy with chapatis, plain or Jeera rice, and salad.