Slice all the vegetables to avial cut. Cook them in a mud pot (preferably) with turmeric powder, chilli powder and salt.
Close and cook in simmer. The moisture in the vegetables are sufficient for the avial to get cooked. If not check in between and sprinkle little water.
Meanwhile grind together grated coconut, cumin, shallots and green chilli coarsely. Not to a very fine paste.
Also beat the curd in a bowl until smooth. Curd has to be sour to get exact taste.
Once vegetables are almost cooked, Add the beaten curd to the vegetables. Toss them gently.
Let it cook until vegetables are completely cooked. Now add ground coconut paste. Toss it gently. Pour in some coconut oil and few curry leaves.
Close it with banana leaf to get a unique flavor. If not just leave it closed for 30 min before serving.