Take the required portion of the idli batter and divide it into three equal parts
Keep one part as such for the white color of the tricolor idli
Chop the tomatoes into chunks
Saute the tomatoes and red chilies for just a couple of minutes for the raw taste to go
Cool it and grind it to a smooth paste
Mix it with one portion of the batter to make the orange color of the tiranga idli
Chop the cilantro (or mint leaves) roughly
Saute it with the green chilies for just a couple of minutes to remove the raw flavor
Cool it and grind it to a smooth paste
Mix it with the third portion of the batter to make the green color of the tricolor idli
To make the tricolor Idlis
You can make separate idlies with the three batters and arrange it in tricolor as shown in the picture
Serve hot