Meanwhile, lay the flour, breadcrumbs and egg on three separate dishes. When the burgers have chilled, heat the oil in a frying pan over medium heat. Dust each burger with flour, egg and then breadcrumbs. The burgers will still be quite delicate, so handle carefully. Shallow fry for about 8 – 10 minutes till golden, turning occasionally. Drain on kitchen paper. They can be kept warm in a low over while you cook the rest.