I am noting down the recipe I tried which is slight modification of original recipe.
Ingredients for 2 servings
4 medium sized button mushroom - finely chopped
1/2 onion finely chopped
1/4 capsicum finely chopped
Salted butter
1/2 cup milk
Salt & pepper as per taste
1. Boil 1 cup water along with milk.
2. Heat butter and sauté onions, mushrooms and capsicum till onions turns pink.
3. Add boiling milk + water mixture and simmer it till the required thickness has formed. Add salt & pepper.