Aviyal is an iconic dish from Kerala. I am not sure if it will qualify as a kadhi (yogurt based dish) or a mixed vegetable. Perhaps a little of both. It can be made in two forms – watery (so that it can be mixed into rice) or thick (to be eaten as an accompaniment to rice with any other wet curry mixed into it). I do not have any particular preference to any specific variety – since both taste wonderful. The method of preparation is the same, it is only the consistency that varies.
Aviyal is made quite often in most Malayalee households. It, however, also holds a special place in the cuisine of Kerala and is one of the dishes made for sadhya (feast) for Onam or Vishu (festivals of Kerala). The best part about cooking aviyal is that it is easy to prepare.

Ingredients
2 cups of mixed vegetables (normally used are raw banana, elephant yam, yellow cucumber, carrot, drumstick, eggplant, potato, chayote squash), cut into 3′ strips
Just enough water to cook the vegetables (2-3 cups)
1/2 tsp turmeric powder (haldi, manjal podi)
Salt to taste
To Grind To A Paste
1/2 cup grated coconut
A small piece of raw mango
1/4 cup vegan yogurt
1/2 tsp cumin seeds (sabut jeera, jeeragam)
2-3 green chillies
To Garnish
1 sprig curry leaves
Method
Cook the vegetables, adding turmeric powder, till done
Adjust the consistency to either a wet curry or a thick dish, using the required amount of water|
Note: If drumsticks and potatoes are done, so will all the other vegetables be
Set aside
Grind coconut, cumin seeds, green chillies, raw mango and vegan yogurt to a fine paste
Add this to the cooked vegetables
Mix well
Garnish with curry leaves
Remove from flame and serve hot
If consistency is thin, mix in with red/brown rice
If consistency is thick, use as an accompaniment to red/brown rice
Enjoy