- Grate potatoes and wash it 2-3 times removing all the starch from it. Drain extra water and pat dry with a cloth. Collect grated potatoes strips in a bowl..add 3 tsp cornflour and required salt in it .mix it properly. Heat the oil in a frying pan over medium to high heat, Drop in large tablespoonfuls of mixture and gently cook for 15 minutes turning halfway through cooking. The rosti should be golden brown and crispy on the outside and the potato cooked all the way through. Add chat masala,cumin powder, rock salt ,red chilli powder,turmeric powder to boiled peas making flowing consistency ragda. Boil for 10 min to blend the flavours well in ragda. Let's assemble now roastie, ragda,curd,chutneys. Take 2-3 potato roastie in a serving plate.. Top it with generous amount of ragda. Add grated carrot,sweet chat turmerind chutney,green chutney ,churned curd on the top. Top it with sev,roasted masala peanuts as much as you want. Serve crunchy potato roastie chat.