Mix all the ingredients for the masala with 1/4 cup water and set aside. Heat oil in a wok. Add the cumin seeds and fry until they crackle [tempering]. Stir in the ginger-garlic paste and cook for a minute. Add the masala and onions, stir well till all onions are coated well with the masala.

Add about 1/2 cup of water and simmer gently on low, uncovered till the onions become tender and most of the water dries up. Stir in the yoghurt, toss well and remove from heat. Stand, covered for a few minutes before serving.