Heat the oil in a wok and fry the onions until golden brown.Lower the heat and add the garlic, turmeric, chili powder, coriander and cumin. Stir fry the spices for about 5 minutes adding a little water if necessary to prevent them sticking to the wok.
Add the salt and tomato puree, mix well and add the mushrooms. Stir until the ingredients are thoroughly mixed. Sprinkle about 2 tblsp water and cover the pan. Simmer for 10 minutes.