First parboil sweet potatoes, potato and raw banana in a pressure cooker upto one whistle with enough water with salt.
Let the pressure release naturally and then place all 3 in a colander. Cool down completely.
Meanwhile, grate raw papaya in bowl.
Stir in the salt, leave for 10 minutes, then squeeze out the extra moisture.
Now grate par boiled potato, sweet potato and banana into raw papaya. To this, stir in red thai curry paste, peanuts, all purpose flour (maida) and coriander stems & leaves.
Mix in all other ingredients - lemon juice, green chillies, coriander powder, salt, red chilli powder and chaat masala.
Test the taste and adjust accordingly.
Bring everything together and shape mixture into small patties, cling wrap and then place on a tray to refridgerate for 30 minutes.
Take out and flatten patties with your palms into small chapati/disc (Flatbread) shape but little thicker than chapati. Your rosti is ready to be shallow fried.
Heat the oil in a large non stick skillet. Shallow fry all, until browned on medium flame.
Serve the rosti with Vegan crema fresca or any dipping sauce of youe choice and chilled Vegan coleslaw salad.