- Place the fish and prawns on a plate and sprinkle with a little sea salt. Cover and refrigerate for 2 hours. This removes excess moisture and helps the burgers bind later.
- Wash the fish and prawns, drain well and finely chop the fish, removing the shell from the prawns and chopping into small chunks.
- In a bowl add the chopped fish, garlic, capers, dill and mustard and mix together in a food processor.
- Form into 4 large burgers, cover with cling film tightly and chill for at 1 hour.
- Using a large frying pan, gently fry the burgers in a little oil, alternatively, you can cook these burgers under the grill or on an open top BBQ.
- For the herb mayonnaise - in a bowl, add the herbs, egg yolk, white wine vinegar and wholegrain mustard. While whisking continuously, slowly add the oil until it emulsifies and thickens.