Heat butter in a pan
Add ginger, garlic paste and fry well
Add onion and fry till golden brown
Add tomatoes and fry until mushy
Add cumin powder, coriander powder, red chili powder, turmeric powder and mix well
Add mushrooms, salt, mix and fry well
Add little water, if necessary and cook mush room until tender
Add garam masala, mix well and cook for additional 2min
Add cream mix well
Garnish with coriander
Serve hot with rice or roti