Teriyaki mackerel skewers

Method

1. Cut the mackerel fillets in half lengthways and lay in a single layer in a glass or ceramic dish. Put the soy, sugar, ginger, spice and half the lemon juice in a small pan and slowly bring to a boil, then simmer for 1 minute. Cool completely, then pour over the fish and marinate for 1 hour, covered, in the fridge, turning the fillets over after 30 minutes.
2. Remove the fillets, reserving the marinade, and pat dry with kitchen paper. Lay on a chopping board and roll up each fillet, skin outwards. Sit 2 rolled fillets next to each other, then thread 2 skewers through each pair (it’s easier to turn food on the barbecue if you use 2 skewers). Brush with oil and put to one side.
3. Mix the remaining lemon juice with the wasabi paste, then stir into the crème fraîche with a little salt. Cook the fish skewers over a hot part of the barbecue, turning once and brushing some of the marinade over them as they cook – they’ll take no more than 2 minutes.
4. Serve with the wasabi crème fraîche, either as a dip or drizzled over the fish, with chives sprinkled on top and lemon wedges on the side.