There are various recipes out there for the oat idlis..some people use Rice + Oats to make these and the other used Oats + Semolina or rava. I made them pretty similar to the 'Rava Idlis' but more of the rava was substituted by oats....
2 cups whole grain quick cooking oats
1 and 1/2 cup Rava
3 and 1/2 cups yogurt
1tsp Baking soda
2 tbsp oil
2 tsp grated ginger
2tsp finely chopped green chilies
1tsp Chana daal
1tsp Urad dal
1tbsp Cashew pieces
6-8 Curry leaves
1tsp mustard seeds
1) Dry roast the oats till slightly brownish.Let them cool.Powder coarsely in a blender.
2) Heat 2 tbsp oil , add the mustard seeds, chana dal, urad dal, grated ginger,green chilies, curry leaves torn into small pieces, cashew pieces and fry till everything is golden brown.
3) Add the rava and roast till it just starts to change color. Let it cool.Add salt and baking soda
4) Mix together the rava mixture with the coarsely ground oats.
6) Spray the Idli pans with cooking spray. Boil water in large pan/steamer for steaming the idlis.
7) For 1 cup of the oats+ rava mixture add 1 cup of yogurt.Mix. The batter is thicker than the usual idli batter. Mix yogurt only to the mixture that will be used up immediately for steaming.Once yogurt is added you have to steam the idlis. If kept longer with yogurt, the soda will loose its action and the idlis will not be fluffy.
8) Steam for 10-15 mins.
9) Serve hot with Sambar and Coconut Chutney