Wash the skinned black gram lentils or urad dal and soak in water for about 4 hours. The lentils will swell up to almost double and be very soft. Drain well and grind to a very fine paste adding very little water.
If your batter seems a little too loose. Mix in a tablespoon or two of semolina (rava) and let it sit for 10 minutes. Using you hand, or a spoon/ fork beat the batter for a couple of minutes till it is well aerated and fluffy. Mix in salt, curry leaves and crushed peppercorns. You may refrigerate the batter at this point till later. Just remember to beat and aerate once again just before making the Vadai.
Once you’re ready to make the Vadai, heat oil in a wok. The oil should be reasonably hot. Shape the Vadai according to your preference with a Vada maker, your palm and fingers or on a banana leaf. This is how I do it.
Dampen your inner inner with water. This prevents the batter from sticking. Pick up a small bit of batter with the fingers of your right hand. Shape it into a rough flattish ball of sorts on your four fingers. Use the tip of your thumb to do this. Then poke a hole in the middle using your thumb. Hold your palm carefully over the oil, inner side facing the oil. The shaped batter will slowly drop off your palm into the hot oil.
Depending on the size of your wok or pot, you can fry about 4 or 5 at a time, or more. Don’t over crowd them in the oil. Fry the Vadai on medium to high heat, turning them over a few times till crisp, done and golden brown.
Remove from oil and let them drain on paper towels. Serve hot with Sambhar and Coconut Chutney.