Wash the sweet potato and then prick it all over with a fork. Then microwave it for 5 minutes. Check if it's cooked and peel and mash it with a fork. Set it aside for now.
Heat oil in a pan. Temper mustard seeds and cumin seeds. Then add and fry urad dal and chana dal along with minced green chillies and curry leaves. Saute till the lentils turns golden brown. So this over a medium flame.
Add ginger and garlic paste to the pan. Continue to saute till the raw smell of garlic goes away.
Next add the chopped onions, part of the cilantro along with salt. Saute till they turn translucent.
Add the mashed sweet potato along with turmeric powder and give it a good mix. Cook for 3-4 minutes. Make sure the mixture is not watery. Check the seasonings and adjust as needed.
Lastly garnish it with cilantro, mix and take it off the flame.
To prepare the masala dosa
Heat a skillet/tawa over a medium flame. Pour a dollop of dosa batter and spread it like a pancake but thinner.
Drizzle oil around the edges. When you see the base has become golden, and the edges separate from the pan, flip it to the other side.
Add a spoonful of the sweet potato mixture in the center, spread it and let it cook for a minute. Fold and close the dosa. Take it off the skillet. Repeat the steps to make as many as you need.
The stuffing mixture is customizable. You can add more veggies like carrots, cauliflower, spinach, paneer, green peas, bell pepper, tofu, etc to it.Smear butter all over the exposed side of the dosa before adding the sweet potato mixture. You can also smear it with green chutney, thecha, or spicy Andhra chutney.The most obvious tip is that you can swap sweet potato with regular potato and make the traditional Masala Dosai. The rest of the recipe remains the same.You can prepare the sweet potato stuffing and the dosa batter ahead of time and store them in the fridge. Bring them to room temperature and then use them as needed.This stuffing can also be used in other recipes like paratha, Frankie, wraps, sandwiches, crepes, waffles, and/or pancakes. You can use this stuffing if you want to eat Rava or Wheat Masala Dosa.Make fresh masala dosai when needed. If you make and keep them, they will get soft and soggy. You can also serve the dosa and the stuffing separately.How to make them crispyAlways keep the flame low to medium when making dosa. There is no need to grease the pan if it's nonstick. Grease it only if using a cast iron tawa.Pour the batter, spread the batter from the center as thin as possible in a circular way. Then drizzle oil or ghee around it.The longer you cook it, it will turn crispy and it will be easy to flip them. If you flip the dosa too soon, it may break or will be soft. Low flame is key here.Reasons for not getting crispy dosaThis can happen if the batter was not well fermented or if the batter is not of the right pouring consistency.Add 1-2 tablespoons of rice flour to the batter if it's too thin and add 1-2 tablespoons of water if it is too thick.How to store itTransfer the leftover dosai batter and sweet potato masala stuffing separately to an airtight container and store it in the fridge for 5-6 days. You can also freeze the leftover batter.