Truth be told, making Indian batters from lentils or pulses is a challenge. The Indian grinder is not available here, nor the ubiquitous mixi with its multiple contains all for a different purpose. My Indian friends pop over to India at least once a year, so their kitchens are purpose built for Indian cuisine.
You will find numerous people advise high speed blenders, like Vitamix, for grinding batters, and I bought one with this in mind (and my old blender had had its day). It was Ok, I have to say, but still hard work. At the same time I bought a popular high-mid-range food processor – high speed with a twin blade. I decided to experiment with it to make batter for these vadai, and am really happy with the result. Quick and easy, no need to use a tamper to push, as with the blender, and I wiped the batter down only twice. There was no need to add extra water. To say I am over the moon is an understatement.
These deep fried vadai, a simple form of Medhu (Medu) Vada, are made from Urad dal with a few spices. They are the type that are soaked in yoghurt for 30 mins – on their own they are a little dry. They can also be soaked in Sambar, or, as I do when I am in a hurry, serve with a bowl of seasoned yoghurt and dip each bite into the yoghurt so that you get a luxurious amount over the vadai.