Mix Ching’s Secret Schezwan Sauce and Ching’s Secret Soy Sauce, chilli flakes, salt and pepper to the potatoes and make small balls of the mixture. Mix besan and water to make a thick batter. Coat each ball with the besan batter and deep fry till crisp. Slice the soft bread roll, coat the inside of bread roll with 1 tbsp. of Ching’s Secret Schezwan Sauce, place the vada in between the layers of the roll and serve hot.