In a kadai, add 2 tablespoons of oil. Fry the 3/4 of the quantity of chopped onions and when they turn pinkish. Add garlic and fry till the raw smell of garlic get emitted.
Add the spices like black pepper corn, cinnamon bay leaf, coriander seeds, cumin seeds and dry red chilies and fry for some time.
Mix the grated coconut and fry till it turns brownish.
Add tamarind and switch off the heat.
Now add turmeric powder and mix well.
After cooling, grind it to a fine paste.
Now in a separate utensil, add 1 tablespoon oil and fry the remaining 1/4 of chopped onion and when they turn pinkish add tomato. When tomato gets mushy add capsicum and fry for 5 minutes. Add the mushroom pieces and fry for 10 minutes.
Now pour the gravy and let it get cooked for another 5-10 minutes. Add salt to taste
Garnish with Kasuri methi and chopped coriander leaves.