Combine water, buttermilk, chickpea flour, sugar, 1 teaspoon asafoetida powder, turmeric, and salt in a microwave-safe bowl; beat into a smooth batter with no lumps remaining.Advertisement
Cook chickpea mixture in the microwave on high for 90 seconds. Beat mixture to break up any lumps. Repeat 3 times, cooking at 90-second intervals and beating after each interval until mixture is slightly thicker than hummus.
Spread mixture into 2 thin 12x18-inch sheets on a clean and dry steel, granite, or marble kitchen counter using a palette knife. Let cool, 5 to 10 minutes.
Cut sheet into 1-inch thick ribbons. Roll up ribbons like a jelly roll.
Heat peanut oil in a saucepan over low heat. Add mustard seeds; cook until they start to pop, about 30 seconds. Stir in curry leaves and 1 teaspoon asafoetida powder.
Spoon oil mixture over rolls.
To test mixture is ready to spread, place a small amount on the back of a dry spoon; let cool. Peel mixture off. If the mixture doesn't peel off easily, microwave for 45 seconds more.
If half of the mixture dries up while you spread the other half, beat it again and microwave for about 1 minute. Check for peeling consistency (see note above). Lumps will be inevitable but the mixture won't go waste.