In Italy this is quite often made with red mullet, but small fillets from mackerel work just as well. The Sicilian version would contain pine nuts and currants in that traditional sweet-and-savoury style. Chilli would be used when currants weren't available and sometimes fried breadcrumbs are scattered on top. It's an ingenious way to make a tasty pasta sauce with a few fish fillets that wouldn't stretch to a full meal.
6 small mackerel fillets, boned and skinned
2 cloves of garlic, peeled and crushed
1 medium chilli, seeded and finely chopped or a good pinch of dried chilli flakes
4 tomatoes, skinned, seeded and finely chopped
100ml extra virgin olive oil
1tbsp chopped fennel tops, or dill (optional)
Salt and freshly ground black pepper
400g or more of fresh or dried tagliolini
Cut the mackerel fillets into small rough 1cm chunks then put them in a pan with the olive oil, garlic, chilli and tomatoes, season and cook on a very gentle heat for 8-10 minutes, stirring every so often until the mackerel are beginning to break down into the oil. Add the fennel leaves or dill and remove from the heat.
Meanwhile cook the pasta according to the instructions and drain, reserving a little of the cooking water to adjust the sauce if necessary. To serve, add the butter to the sauce, re-season if necessary and toss the spaghetti in with the mackerel and chilli sauce.