Wash, drain, and dry the rice.
Boil the water, salt, and turmeric in a 2-liter/quart saucepan over moderate heat.
Heat the oil over moderately low heat in another 2-liter/quart saucepan. Saute the raw cashew halves or bits in the hot oil until they turn golden brown. Remove them with a slotted spoon and put them aside.
Saute the mustard seeds in the remaining hot oil until the mustard seeds crackle.
Add the rice and saute for 1 or 2 minutes, or until the grains are evenly whitish in color. Add the boiling salted turmeric water. Stir, raise the heat, and bring the water to a full boil. Immediately reduce the heat to low, cover with a tight-fitting lid and gently simmer, without stirring, for 15 minutes or until all the water has been absorbed and the rice is tender and flaky.
Remove the rice from the heat, leaving the lid on for another 5 minutes to allow the rice to firm.
Before you serve the rice, fold in the cashew nuts, coconut, lemon or lime juice, and fresh herbs. Serve hot.