Heat 1 tablespoon of oil in a skillet over medium-high heat. Add the quartered mushrooms and cook without moving them frequently until they release their moisture and turn lightly browned, about 5 to 7 minutes. Remove the mushrooms from the pan and set them aside.

In the same pan, add the remaining 1 tablespoon of oil. Add the cumin seeds and let them sizzle for a few seconds. Add the finely chopped onions and cook, stirring occasionally, until they turn light golden brown.

Stir in the ginger-garlic paste and cook for about 1 minute until the raw smell disappears. Reduce the heat slightly and add the turmeric powder, coriander powder, and Kashmiri chili powder. Stir well for 30 seconds.

Add the pureed or finely chopped tomatoes and salt. Cook the mixture, stirring often, until the tomatoes soften and the oil begins to separate slightly from the edges of the masala, about 6 to 8 minutes.

Add the seared mushrooms back into the pan and mix to coat them well with the masala. Pour in 1/2 cup of water, bring to a gentle simmer, cover, and cook for 5 minutes so the flavors meld.

Crush the kasuri methi between your palms and sprinkle it over the curry along with the garam masala. Stir well, cook uncovered for 2 more minutes, and remove from heat. Serve hot.