Heat oil in pot. Add mustard seeds & leave them for 10 to 20 seconds. Add rice & peas (if using fresh) & stir-fry for 1 minute. Add water & salt. Cover & bring to a boil, reduce heat to very low & cook till the rice is almost done, 15 to 25 minutes depending on the type of the rice & the amount of heat used. If using forzen peas, thaw them under running hot water. Add to the rice about 5 minutes before the cooking process is finished. Mix & serve with dal & vegetables. Madhur Jaffrey, "An Invitation to Indian Cooking"