- 250g/9oz colcannon or mashed potato
- 250g/9oz potatoes (such as Rooster), peeled and grated
- 100g/3½oz plain flour
- 125ml/4fl oz milk
- knob of butter
- rapeseed oil, for frying
- sea salt and freshly ground black pepper
- 4 small mackerel, gutted and butterflied or filleted
- 2–3 tbsp olive oil
- 3 garlic cloves, finely chopped
- knob of butter
- dill, chopped, to garnish
- 1 lemon, juice only, to serve
- ½ head frissee lettuce, inner leaves removed
- 3 tbsp olive oil
- 1 tbsp white wine vinegar
- 1 tsp Dijon mustard
- For the boxty, put the colcannon (or mash), grated potato and flour in a bowl and mix until combined. Stir in the milk, little by little, until you have a wet dropping consistency. Season with salt and pepper.
- Heat a frying pan over a medium–high heat. Add a little butter and oil, when the butter begins to foam, spoon heaped tablespoons of the mixture into the frying pan and fry for 3–4 minutes on each side until golden-brown.
- Remove and place on a warm plate lined with kitchen paper. Repeat with the remaining mixture. Keep the pancakes warm in a low oven, if necessary.
- For the mackerel, coat the mackerel fillets with a little oil and garlic. Season with salt and pepper.
- Heat a frying pan over a high heat and add a splash of oil and the butter. When the butter is foaming, add the mackerel skin-side down and fry for 3–4 minutes until the skin is crisp and the flesh is opaque.
- Meanwhile, make the salad. Place the lettuce leaves in a large bowl. Mix the oil, vinegar and mustard in a small bowl. Season with salt and pepper and pour over the leaves. Toss to coat.
- Serve the mackerel with the potato pancakes. Finish with a little dill over the pancakes and a squeeze of lemon juice on the fish.