Cebollas Rellenas de Bonito

Cebollas rellenas de bonito are Asturian, from the Nalón mining valleys, and they are not just any stuffed onion. The onion is hollowed, filled with bonito del norte, hard-boiled egg, piquillo pepper, and a little tomato, then cooked slowly in a cider-tomato sauce until the outside goes tender and sweet. This is cocina de vigilia, meatless cooking for days when the pot still had to feed people properly.

The method that decides it is the hollowing and the braise. Leave two firm outer layers so the onion holds its shape, then cook it low and covered until a knife slips through with no fight. Rush the sauce and the onion stays sharp. Give it time and it becomes the dish: sweet outside, savory within, the bonito carrying the sea without shouting over the cider.

If you can't find bonito del norte where you are, use good tuna packed in olive oil, not dry tuna in water. It will be a little less delicate, but it will still behave honestly in the filling. Piquillos matter if you can get them; roasted red pepper is the plain substitute and brings sweetness without pretending to be the same thing.

Make them ahead if you like. They settle beautifully overnight, and the sauce thickens around the onions in the way my notebook always marks as worth waiting for. Siempre sale, si lo sigues.