There is actually nothing to this recipe. All you have to do is take the cooked rice in a bowl and cover it with cold water. The water should be at least a cm above the rice. Cover it with a plate and leave it overnight.
Finely slice your onions and lemon wedges. Serve the panta bhat with sliced lemon wedges, sliced onions, mustard oil and salt.
Don’t throw the water. The water is the best part since it has all the nutrition and the tanginess comes from the water. Crush everything together in the plate or a bowl with the water and have it.
If you want, of course fry a fish alonside and have with it. There are a variety of ways to have it. Some even have it with tamarind instead of lemon wedges. So go ahead and experiment and try various flavours.