Take a pan add oil..saute fresh chopped garlic, curry leaves and shezwan sauce...mix well..now add soya sauce,red chilli sauce,vinegar,green chilli sauce and tomato ketchup..keep on mixing it..lastly add chopped spring onions..mix well..if you feel it's too thin add the left over mixture of cornflour by adding little water to it..and add this cornflour mixture to the gravy..so the gravy vl thicken..add cripy potatoes mix very gently..