Skagenröra Norwegian prawn and crayfish salad recipe

Ingredients

• ½ red onion, finely chopped or sliced
• 1 x 85g jar rainbow trout caviar or red lumpfish roe*
• 2 x 80g packs crayfish tails, drained
• 250g peeled cold-water prawns, defrosted
• 3 tbsp finely chopped chives
• 3 tbsp chopped dill
• a few good handfuls of mixed leaves, to serve
• 3 tbsp full-fat mayonnaise
• ½ tbsp Dijon mustard
• 3 tbsp soured cream
• ½ tbsp Worcestershire sauce
• ½ tbsp caster sugar
• juice of ½-1 lemon, to taste