In a hot pan or wok, flash fry the vegetables and remove them from the pan. Place the squid and mackerel in the pan and cook for 30 seconds then remove from the pan.
In a bowl, mix the hot fish and vegetables with the fish sauce, peanuts, lime juice, ginger and sesame seeds and set aside to cool.
Mix the flour into the water and stir to make a thin paste. Lay out the pastry sheets and brush each one all over with the flour paste. Divide the fish mixture into five portions, wrap each one in a sheet of pastry then wrap each roll in a second sheet of pastry.
Heat the oil to 180C/350F in a deep-fat fryer or large saucepan then fry the rolls until golden-brown and crisp. Drain the rolls on kitchen paper. (CAUTION: Hot oil can be dangerous. Do not leave unattended.)
To make the dipping sauce, mix together all the ingredients in a bowl until well combined.
Serve the rolls immediately with the dipping sauce alongside.