Step 1

Cut the fish into 4 chunky fingers. Put the flour in a bowl with some seasoning, put the egg in another bowl, and the breadcrumbs and sesame seeds in a third. Dust the fish fingers in flour, then dip in egg and, finally, coat in breadcrumbs. Chill for 10 mins, if you have time.

Step 2

Heat a drizzle of oil in a frying pan and cook the fish fingers for 3-4 mins each side until golden and cooked through, adding a drizzle more oil if the pan looks too dry.

Step 3

Meanwhile, stone, peel and slice the avocado, squeeze over a little of the lime juice to prevent it from turning brown, then mix the remaining lime juice and coriander into the mayonnaise.

Step 4

To serve, spread a little mayo over the base of each bun, top with 2 fish fingers, a few slices of avocado and the bun lid. Serve the remaining mayo on the side.