4 mackerel, gutted and cleaned
1 tbsp coriander seeds
1 tbsp cumin seeds
4 garlic cloves, peeled
2 tbsp paprika
1 preserved lemon, plus a splash of the liquor from the jar
1 small bunch of parsley, roughly chopped
1 small bunch of coriander, roughly chopped, with a few leaves reserved for garnish
1 tsp tomato purée
40 ml / 2½ tbsp olive oil
Lime wedges, to serve
Preheat the oven to 160 °C fan / 180 °C / 350 °F / gas mark 4. Alternatively, bring a barbeque up to temperature.
Using a sharp knife, score the mackerel along both sides of the body and season with a little salt.
Heat a heavy-based frying pan (skillet) over a medium heat and toast the coriander and cumin seeds until fragrant (about 1 minute), then transfer to a spice grinder or pestle and mortar and crush. Add the crushed spices to a food processor, along with the garlic, paprika, preserved lemon, a splash of the lemon-preserving liquor, parsley, chopped coriander, tomato purée and olive oil, and blend for 1 minute.
Line a roasting pan with some greaseproof (wax) paper and place the mackerel on top. Rub the spice paste over the mackerel and into the scored flesh.
Roast in the hot oven for 8 minutes. Alternatively, cook over the hot barbeque for about 4 minutes on each side.
Transfer the fish to a serving plate, and garnish with the reserved coriander leaves and lime wedges.