One small fish fillet per sandwich
Crusty roll or a part of a not-too-crusty baguette
Leaf lettuce, arugula or watercress
There is no one true recipe for this, as best I can tell. I like it with some mayonnaise, into which I mix some ají amarillo paste, but others just like olive oil or tsatsiki. Some like to add thinly-sliced red onions. Like any great sandwich, the details are best left to the consumer.
On an oiled griddle, cook an oily fish fillet, like Boston Mackeral or a piece of Bluefish from the tail end, where it’s thin and has fewer bones. Cook it on both sides, browning each and seasoning with salt and pepper.
Meanwhile mix mayonnaise and a spicy sauce like ají amarillo paste (3:1 ratio, I’d guess) and spread on a crusty roll or a 2 pieces of toast. Place cooked fish on the bread, add washed greens. A tomato slice will complete the sandwich, but don’t bother unless it’s perfectly ripe and tasty — you’ll just ruin the whole thing.