Ingredients

• ½ cucumber
• peeled
• thinly sliced on a mandoline
• salt
• 4 tbsp grated fresh horseradish
• 2 heaped tablespoon crème fraîche
• 2 tsp English mustard powder
• 4 fresh mackerel fillets
• salt and freshly ground black pepper
• knob of butter
• 4 slices soda bread
• toasted
• buttered
• 1 small red onion
• thinly sliced
• ½ small lemon

Directions

• For the salted cucumber and horseradish
• place the cucumber slices into a colander and sprinkle with plenty of salt. Mix well and leave the contents to drain over the sink for half an hour.
• Rinse the salt off the cucumber with cold water
• then leave to drain. Gently wring out any excess moisture from the cucumber with your hands
• then set aside.
• In a clean bowl
• mix the horseradish with the crème fraîche and mustard powder
• making sure the mustard powder is well combined with no lumps. Set aside.
• Season the mackerel fillets on their skin side with salt and freshly ground black pepper.
• Heat the butter in a frying pan until it is foaming
• then add the fillets skin-side down. Place a heat-proof plate onto the cooking fillets
• as this will make sure they stay flat and cook evenly. Cook for 4-5 minutes
• or until nearly cooked through
• then turn the fillets and cook for 30 seconds
• or until just cooked through.
• To serve
• place a small handful of the cucumber onto the toast. Place the cooked mackerel fillets onto the cucumber. Place a dollop of the horseradish sauce on top and garnish with a little of the sliced red onion and a squeeze of lemon.