1.Slice the fish into 1cm-wide strips. Whisk the eggs and milk together, then season.
2.Dust the fish in the flour and shake off the excess. Dip in the egg and milk, then roll each slice in the breadcrumbs with herbs. Repeat the process. Refrigerate the fish to help the crumbs stick to the fillets.
3.To make the tartare sauce, stir all the chopped ingredients through the mayonnaise. Season to taste.
4.Heat the frying pan and add the oil in a shallow layer. Cook the fish, turning once, for about 5 minutes, until they are brown and crispy. Remove and place on paper towels to drain.
5.Spread the bread liberally with the tartare sauce. Add a layer of fish fingers and lettuce.