Wash and rinse all the ingredients (except for the salt) for the dosa batter in a large mixing bowl. Pour enough water and soak them for at least 4 hours.
Grind the ingredients into a very fine paste using little water. I use my Ultra Grind mixer for this -- add all the ingredients and enough water, forget it for about 25~30 minutes. If using mixer, then grind in batches to get the required consistency.
Pour the batter into a large bowl, cover and set aside for at least 12 hours. Batter needs to be nicely fermented to get crispy dosa.
Heat 1tbsp oil in a pan, add cumin seeds and once they start to splutter, add ginger and green chilies. Cook for 30 seconds.
Next add the tomatoes, turmeric and salt. Stir well and cook till tomatoes are slightly tender, but not mushy about 1~2 minutes.
Stir in paneer cubes and ½cup water. Bring to a boil then lower the heat, cover and simmer for 5 minutes.
Stir in the peas and cilantro and cook for 1~2 minutes. Remove from heat and set aside until ready to use.
Heat a large nonstick or cast iron tawa or griddle on high heat. Ladle ½~¾cup dosa batter in the middle of the pan and spread it out in a circular motion using the back of the ladle. Make the batter as thin as you can for the most crispy dosa. Drizzle with oil on top.
Cook on medium-high heat until dosa is golden brown and starts to peel off from the pan, takes about 1~2 minutes. Use a spatula to flip it over and cook for another 1 minute.
Place some of the paneer filling on one half of the dosa and cover it with the other half. Remove from pan and serve right away. Repeat with the remaining batter.