Prepare the batter for the rava dosa by mixing rava, rice flour, maida, salt, cumin seeds, chopped onions, green chilies, coriander leaves, and ginger. Mix it well and let the batter sit for 30 minutes. Heat a non-stick pan, pour a ladleful of batter, and spread it thin. Drizzle some oil on the top and let it cook. Serve hot with coconut chutney and sambhar.