Rinse the rice and drain. Bring the rice, water, and salt to a boil and cook over low heat, until all the water is absorbed. Remove from heat and let stand, covered, for 10 minutes. Fluff the rice with a fork.
Heat the oil in a 12-inch frying pan over moderately high heat. Cook the mustard seeds, stirring until the seeds begin to pop. Add the ginger and peanuts, and stir another 2 minutes. Add the turmeric, and stir one minute more.
Add the spice mixture to the cooked rice and mix thoroughly.
Stir in the lemon juice and sprinkle with the lemon zest.