- Pop the trout in a frying pan with the milk, stock and spring onions. Simmer for 5 minutes or until the fish is cooked. Lift the fish out of the pan and set it aside. Strain the stock through a sieve into a bowl, setting aside the spring onions (discard the liquid).
- Put the potato in a bowl and stir in the tartare sauce, egg and breadcrumbs. Flake the trout and add to the potato mixture, together with the spring onions. Fold into the potato mixture and season with salt and pepper.
- Divide the fish mixture into eight and, using your hands, shape into burgers – kids will love to help with this part. Coat each burger in the semolina and pat them into shape. Arrange on a plate and put them in the fridge for 1 hour to firm them up.
- Heat the oil in a non-stick frying pan and fry the burgers in batches, for about 10 minutes, turning once. Place on kitchen paper once cooked, to drain off any excess oil.
- Mix the mayonnaise with the sweetcorn and red pepper.
- To serve, spread the bottom half of each bun with a little of the mayonnaise. Top with a few salad leaves, a tomato slice, the burgers and the remaining half of the bun.
Ketchup is an easy swap for tartare sauce in the burger mixture if the kids don't like it.