In a pan heat the oil and butter. Add the cumene seeds and then the onion and fry till translucent. Add the tomatoes and fry for 2 minutes. Add the masalas- cumene, coriander, chilli powder and fry for xbd a minute.Add the soaked Masoor dal along with the water. Cover and cook till the Dal is done. It takes about 10-15 minutes for the dal to be cooked.Adjust the required consistency of the by adding or evaporating the water.