Wash the urad dal for 3-4 times and soak for 3 hours.
After one hour keep the urad dal in fridge till you are ready to grind.
Take ginger and green chilli in mixer
Grind to coarse paste
Now add urad dal to the mixture.
Grind the batter scraping the sides adding little water.
Grind to smooth and fluffy batter.
Transfer the batter to bowl.
Now add salt, onions, cumin seeds, pepper powder, curry leaves and coriander leaves.
Mix the batter nicely till everything combined.
Heat oil a kadai.
Dip your hands in water and take batter and flatten them in your hands and put holes in the center resembling doughnuts.
Drop the vadai in oil and fry till golden and crispy flipping in between.
Drain them in tissue.
Crispy and fluffy medu vada is ready.
Serve it with chutney or sambar.