First lets prepare potato curry. For that make paste of mustard and garlic by adding just enough water
Peel potatoes and cut them lengthwise
In a pan heat mustard oil add mustard garlic paste and fry till oil separates.
Add coriander, chilli and turmeric powder, fry for a minute
Sprinkle little water so that masala doesn't get burned
Add chopped tomatoes and salt
Fry till tomatoes get soft and mushy
Add potatoes and hot water
Adding hot water to curry helps not to drop down the temperature
Cover and simmer until potatoes get cooked and gravy is of desirable consistency, not too thick gravy is preferred with dhooska.
To make dhooska soak rice and dal together atleast for 4 hours
Drain, add ginger and green chillies and make a batter
Batter should be of dosa batter consistency
Add whole cumin, salt and 1 pinch termeric
Heat up oil in a kadai
Oil should be hot, pour one big spoon of batter in the center of hot oil
Batter will start rising like a puri, press gently and fry until corners get slightly crispy
Take out on a kitchen towel to drain excess oil
Serve dhuska hot hot with prepared potato curry oozing out the aroma of mustard oil with some fresh coriander leaves on top.
Dhooska is also eaten with mutton curry as non vegetarian option