Rinse lentils until the water runs somewhat clear. Drain out the water. Add the lentils to a medium pot. Grind the whole coriander seeds with a mortar and pestle or spice grinder, and add to the pot.
Cover the pot, and heat on the stove over medium high until it begins to boil. Once boiling, remove the lid, reduce the temperature to medium/medium-low and gently boil for 10-15 min, or until the lentils absorb most of the liquid. Turn off the heat, cover and let the lentils sit for 5 min to continue absorbing the liquid without becoming mushy.
Taste and season to preference with additional salt and pepper. Serve immediately. Garnish with fresh cilantro or dill.