You want to use tiny, tasty Spanish sardines for this dish – I particularly like the 'sardinillas' from Brindisa in London's Borough Market; otherwise any good sardines in olive oil will do.
1 small can of sardinillas
2 slices from a sourdough loaf
1tbsp capers, rinsed
Toast the bread on both sides, arrange the sardines on the bread with some of the oil from the can and scatter the capers on top.