Wash and soak the rice and urad dal separately for 6 hours.
When ready to grind, first grind the rice to a coarse texture. Remove and then grind the urad dal to a smooth texture. When the urad dal is ground, mix in the rice and grind both together for 5 mins.
We usually use wet grinder for grinding, you can grind this in a mixer jar as well. The water used should be just enough to grind and should limit to 1 cup of water maximum.
Making the Tempering
Grind the ginger and green chilies to a paste. Add cumin seeds, curry leaves, salt and ginger, green chili paste along with finely chopped onions to the batter, mix well and keep it ready.
Making Dibba Rotti
Heat a deep sauce pan with 2 tsp cooking oil, simmer and pour a ladleful of batter, slightly press it around. Sprinkle cooking oil on the sides, cover with lid and let it cook. It takes about 2 to 3 mins for one side to get cooked.
Carefully flip to the other side and again cook for 2 to 3 mins with the cover on.