In a mixer take ash gourd pieces and coconut. Grind them together to fine puree. Do not add water at this stage.
Rinse soaked rice twice with enough water and drain it off. Include this rice and rice flakes also to the mixer and grind finely to obtain dosa batter. Transfer the batter to a container, add turmeric powder and mix well. Ferment the batter for about 8 to 10 hours.
The fermented batter would have raised, check the consistency. If required add little water to bring it to dosa batter consistency. Add salt and mix. Heat a dosa griddle, smear some oil and pour a ladle full of batter on it. Using back of ladle, spread it in dosa form.
Drizzle some oil over the dosa, cook it covered for about a minute. Flip to cook other side and remove from the griddle.
Very healthy and lentil-less ash gourd dosa is ready to devour with chutney of your choice.