Put the urad dal in a deep bowl with cold water to cover dal by about 3 inches. Using the palms of your hands, rub the dal to split them apart. Allow them to soak for at least 8 hours. Drain well, reserving about half of the soaking water. Place the dal and half of the water into a food processor fitted with the metal blade. Process until very thick and smooth, adding additional soaking water as necessary. Add salt. Pour 1 tablespoon of the oil in a nonstick griddle over medium heat, tilting the pan so the oil covers the entire bottom. When hot, pour spoonfuls of dal butter onto the griddle to make round blinis 2 1/2 inches in diameter. Do not crowd the pan. Cook for about 1 minute, or until the batter is set and the bottom is lightly browned. Turn the blinis and cook for an additional minute, or until they are cooked through. Remove from the griddle, place on a warm plate, and loosely tent with foil to keep warm. Continue to grease the griddle and cook the blinis until you have 18. Place 3 blinis, slightly overlapping, on 6 small plates. Place a spoonful of caviar in the center of each blini. Place a chive point into each mound of caviar and serve.