Dry roast peanuts in a fry pan until golden brown.

Grind peanuts, chilies, tamarind paste, and salt into a smooth paste with water for chutney.

Transfer chutney to a bowl.

Heat oil until sizzling, add mustard seeds and hing until they pop. Pour over the chutney.

Boil cubed potatoes until fork tender, drain, and set aside for the filling.

Heat oil over medium-high heat, add mustard and cumin seeds.

Add chopped onion and green chilies, saute for a couple of minutes.

Add ground cumin and coriander, mix gently stir in the cubed potatoes.

Add turmeric, garam masala, chopped cilantro, mix well.

Add a little water to thin the mixture and salt to taste. Keep warm.

Place the urad dal and basmati rice in separate bowls and cover with water. Let sit at room temperature overnight.

In the morning, drain and rinse the rice and dal. Grind them together in a food processor.

Add onion, chili, and salt; continue to grind. Add water until you get a smooth, creamy, slightly thin batter.

Heat a large, flat, oiled griddle over medium-high heat.

Pour 1/2-3/4 cup of batter into the center of the griddle, swirl outwards into a thin pancake.

Cook until the underside is golden brown and the top is no longer glossy.

Remove the dosa from the pan, fill with potato filling and sriracha.

Roll up and serve immediately with the peanut chutney.