Heat oil in a pan or a kadai.
Splutter mustard seeds.
Add curry leaves and saute for a while.
Add onions and fry, till golden brown.
Add ginger-garlic paste and saute further.
Add turmeric powder and pepper and fry for a couple of seconds.
Add mushrooms and 1/2 glass of water.
Add salt and mix well.
Cook, till the mushrooms are done.
When done, add lime juice.
Garnish with coriander leaves.
:- Serve with rotis, naan or malaysian parathas.
:- You can add chopped potatoes with the mushrooms to increase the quantity.