Crunchy Sardine Sandwich

A cold sandwich with no cooking at all, which is why it turns up in an outdoor cooking book. The only real decisions are the tin you buy and how thinly you slice the radishes.

• Smoked Scandinavian sardinesThese are the small brisling or sprats packed in oil, usually labelled smoked brisling sardines and sold in flat tins. They are firmer and darker than the plain-packed Portuguese or Moroccan sardine, and the smoke is doing most of the work here. Drain them on paper towel or the bread turns to paste.
• Chili sauceIn American cookbooks of this era chili sauce means a thick, sweet-sour tomato relish closer to cocktail sauce than to hot sauce, with onion, vinegar and mild spice. Ketchup with a little vinegar and a pinch of cayenne is the nearest supermarket substitute; a hot pepper sauce is not.
• Butter both slicesThe butter is a moisture barrier as much as a flavour, which matters if the sandwich is being carried in a basket. Have it properly soft so it spreads without tearing the bread, and take it right to the edges.
• RadishesSlice them paper-thin on a mandoline or with a sharp knife and use them at once. Cut ahead of time they weep and go limp, and the crunch of the title is gone.
• BreadA firm white sandwich loaf or a light rye holds up best. Anything very open-crumbed lets the oil through.
• YieldThe recipe gives no yield. A standard tin of brisling sardines will generally stretch to about two sandwiches, or four halves for a picnic.
• Make it close to the timeThis does not improve on standing. Assembled more than half an hour ahead, the radish water and the sardine oil both migrate into the crumb.