Masala Dosa

Before you start

• Plan two days ahead. Soaking is 6 hours and fermentation is 8-14 hours depending on how warm your kitchen is.
• The batter is fermented, not raised with anything added. In a cold kitchen, leave it in an oven with only the light on.
• You will know it is ready when the batter has roughly doubled, smells pleasantly sour, and is full of bubbles.

Method

1. Soak the rice in one bowl, and the urad dal with the fenugreek in another, for 6 hours.
2. Grind the urad dal first with a little cold water until very light and fluffy, then the rice to a slightly grainy paste. Combine, add salt and mix with your hand for a minute; the warmth helps it start.
3. Cover loosely and leave in a warm place 8-14 hours until doubled, bubbly and faintly sour. Stir gently before use and thin with water to a pouring consistency.
4. For the filling, heat oil, splutter the mustard seeds with the chana dal, curry leaves and asafoetida, add the onion, chilli and ginger and cook until soft. Add turmeric, then the crumbled potato, salt and coriander. Keep warm.
5. Heat a flat tawa until a drop of water skitters across it. Rub with a halved onion dipped in oil, pour a ladle of batter in the centre and spread outwards in a quick spiral.If the batter will not spread, the pan is too hot; cool it briefly with a wipe of a damp cloth.
6. Drizzle oil around the edge and cook until the underside is crisp and deep gold, 2-3 minutes. Do not flip. Place a scoop of potato in the centre, fold and serve straight away with coconut chutney and sambar.

Storage

Fermented batter keeps 4-5 days refrigerated and gets more sour each day; older batter suits dosa better than idli. Cooked dosas do not keep. The potato filling keeps 3 days.