Urad dal / Ulundu vadai is a very common breakfast item in South-India. With this basic vada we can make sambar vada or dahi vada. Again, this is my MIL's recipe and she is so good at it. Try it for yourself and you will surely agree with me.
I'm adding this after seeing Asha's comment. I did not know that this is a karnataka dish too and goes by the name ' Uddin Vade'. So, now I'm sending this for RCI:K.
urad dal- 1/4 kg
ponni raw rice- 1 tsp
salt- as required
Soak urad dal for 5 to 6 hours. Drain and grind it with rice to a smooth paste (like butter). Add finely chopped onions, green chillies, ginger, corriander and curry leaves. Do not add salt while grinding the urad dal. Salt should be added after the batter is ready . If not the batter will give away the water and make it runny.Oil your palms and shape the batter into vadas. You can use a ziploc cover too instead of your hand. Slide it carefully in the oil and deep fry it. Serve it with coconut chutney.