Arachuvitta sambar is a flavored sambar, that goes very well with rice and dosa. Potato curry is the best combination for this. Here we roast and grind a few spices along with coconut, then add that paste to a plain sambar. That's why it is called as arachuvitta sambar.
You can use vegetables like Ladies finger, Chow chow (Vegetable pear), Drumstick, Pumpkin, Broad beans (Avaraikkai) to make this sambar. Here I have used chow chow.