Wash, clean and keep the mushrooms aside. If they are big, cut them into halves.
In a pan, add 2 cup water along with halved tomatoes, whole garlic cloves, green chili and the piece of ginger. Add the kashmiri red chili powder, butter and cover the pan. Simmer this mix on low flame for about 20 minutes.
Switch off the flame after 20 minutes and wait until the mixture is cool. Transfer to a blender and grind this into a smooth puree.
Heat a heavy bottomed pan. Add 1 tablespoon ghee. Once warm, add the chopped onions and saute them until light golden brown. Add the tomato puree, mix well and let this simmer covered for about 5 minutes. At this point you may add a teaspoon of kashmiri red chili powder too for color (optional).
Add the mushrooms to the puree and let them cook for about 10-12 minutes covered on low to medium flame.
Feel free to add half or one cup of warm water depending upon your desired consistency.
Once the mushrooms are cooked, add a tablespoon of kasuri methi and mix well. Let the mushrooms simmer for another 5 minutes after which you may switch off the flame. Keep the pan covered for about 15 minutes.
Garnish with chopped coriander leaves and serve hot with either steamed rice or hot rotis and some refreshing raita on the side.