Roast potatoes, mackerel and kale with horseradish and caper mayonnaise

SERVES 4

750g small new potatoes

125g curly kale, stems removed and patted dry

3tbsp olive oil

4 garlic cloves, root trimmed ¾tsp fennel seeds

½tsp dried green peppercorns 4 large mackerel fillets juice of ½ lemon

½tsp sea salt

1tbsp small capers

For the horseradish and caper mayonnaise

3tbsp mayonnaise

2tbsp creamed horseradish 1tbsp capers, roughly chopped

In a bowl, mix the horseradish and mayonnaise then pour over the chopped capers.

Preheat the oven to 200C/ 400F/Gas 6. Cook the potatoes in boiling water for 15 minutes. Meanwhile, put the kale in a roasting tin and toss with 1 teaspoon of the olive oil and cook in the oven for 5 minutes until crispy. Tip on to a plate and wipe the roasting tin clean.

When the potatoes are ready, drain in a colander, cover with the pan and leave for a few minutes. When they look dry, tip into the roasting tin, add the garlic and spoon over 2 tablespoons of the oil. Roughly crush the fennel seeds and green peppercorns then scatter over the potatoes.

Using the back of a wooden spoon, flatten the potatoes lightly so they squash and split. Toss everything together and roast for until golden, about 10 minutes.

While this is happening, cut a V shape either side of the dark line in the middle of the mackerel fillets and remove the line of pin bones without cutting through the skin. Season the flesh side of each fillet with salt and lemon juice then cut in half crossways. Leave to rest for 5 minutes then spoon over the rest of the oil and rub into the skin.

Take the roasting tin out of the oven, add the fish skin-side up and cook for a further 10 minutes.

Add the capers and kale to the fish and potatoes and cook for 3 minutes. Place on a platter and serve with the horseradish and caper mayonnaise.