Prepare Dosa Batter:Soak rice and urad dal in separate bowls for 4-6 hours. Strain.

Process rice and urad dal mixture in commercial grinder or food processor. While grinding, add water a cup at a time until it reaches the consistency of pancake batter. Salt to taste.

Cover mixture and let sit overnight. Do not refrigerate; it needs to ferment.

Prepare Masala Dosa Filling: Add oil or ghee to a skillet.

Add mustard seeds and chana dal.

Shake mixture over the flame until golden brown.

Add curry leaves (whole leaf), green chiles, and onions.

Sprinkle turmeric powder and salt (for taste). Stir.

Break up boiled potato into small chunks and add them to your mixture. Add water and stir.

Prepare Masala Dosa: Pour refrigerated dosa mixture into a small bowl with a flat bottom.

Pour batter into a greased skillet.

Immediately, starting from the center, begin forming a circular shape with the batter using the flat-bottomed dish.

Brush on ghee (or regular butter) to frying dosa.

Place filling near the center of the dosa.

Lightly lift the edges of the dosa.

Begin rolling from the edge of the dosa as you would a wrap.

Remove dosa from hot top or skillet.

Masala Dosa is typically served with coconut, cilantro and tomato chutney as well as sambar (vegetable lentil stew)