Instructions

Gather the ingredients.

Heat the cooking oil in a heavy-bottomed pan on medium heat.
When hot, add the onions. Sauté till the onions begin to turn a pale golden brown in color. Remove from the oil with a slotted spoon and drain on paper towels. Turn off heat.
Grind the onions in a food processor into a smooth paste, adding very little to no water. Transfer to a separate container and reserve.
Grind the tomatoes, garlic, and ginger pastes together in the food processor to a smooth paste. Transfer to a separate container and reserve for later use.
Reheat the oil left over from frying the onions and add the reserved onion paste. Sauté for two to three minutes.

Add the tomato paste, coriander, cumin, turmeric, red chili powder, and garam masala powder and mix well.
Sauté the resulting masala (onion-tomato-spice mixture) until the oil begins to separate from it. This can take up to 10 minutes.

Now add the lamb pieces to the masala, season with salt to taste, and stir to fully coat the lamb pieces with the masala. Sauté until the lamb is browned well.

Add 1/2 cup of hot water to the pan and stir to mix well. Bring to a boil, reduce the heat to a simmer, and cover the pan. Cook until the mutton is tender. You will need to keep checking on the lamb as it cooks and adding more water if all the water dries up. Stir often to prevent burning. The dish should have a fairly thick gravy when done
When the lamb is cooked, garnish with chopped coriander and serve with hot chapatis (Indian flatbread), naans (tandoor-baked Indian flatbread), or plain boiled rice.