To begin making the chhatu besara recipe first clean the mushrooms throughly under running water .Soak them in turmeric powder for 10 mints. Then cut them into small pieces. Peel the potatoes & chop it into small pieces. Keep it in a bowl of water until it is needed. Next prepare the mustard ,poppy seeds paste .Place all the ingredients listed under for this paste into a blender & grind to a fine but thick paste with a little water. Now to begin making the curry add about 2 tbsp of oil into a kadai. First add the potatoes ,sprinkle some salt & saute until they are almost cooked. Transfer them into a bowl.In the same kadai add the chopped onions ,chopped tomatoes , toss them for a mint & then add the chopped mushrooms .Saute them in high heat for 6 to 8 mints ,until the mushrooms are half cooked.Add the roasted potatoes , turmeric powder & toss together for another couple of mints. To this add the prepared mustard ,poppy seeds paste,mix well & saute for 2-3 mints.Add salt & required amount of water to the gravy .Allow the curry to come to a boil.Simmer the oriya chhatu besara on low to medium heat for about 5 mints until the masalas get well absorbed by the vegetables .Garnish with chopped coriander leaves. Serve hot with steam rice or phulkas.