Mix all the ingredients for batter. The batter should be little thick. Coat all the mushrooms in this. Fry in hot oil till golden. Drain and set aside.
Heat oil in a pan. Add in garlic, onions, green chillies. Saute for a min.
Add in bell peppers and saute for 2 to 3 mins.
Now add in all the sauces, vinegar pepper, salt, sugar and mix well.
Add in water and bring it to a boil.
Add in fried mushrooms and mix well. Add in cornflour slurry and mix well