Heat butter and fry the onions and garlic till soft.
Chop half of the mushrooms coarsely and add to it. Fry for about 5 minutes.
Add the flour while stirring well. Cook for another 5 minutes.
(*For making veg stock:-
Mix everything in a pressure cooker, cover it with lid and boil for 15 minutes. If you want to make a clear soup, don`t mash it. Turn off the gas. Strain using a strainer. Use the liquid for making soup.)Gradually add the stock and bring to a boil.