Mention tinned fish to most Americans, and they’ll probably think of nothing more than a tuna sandwich. But the Spanish and Portuguese have long enjoyed seafood conservas as a simple, elegant snack, having spent generations mastering quick-canning techniques for sardines, clams, and other delicacies.

Conservas have begun appearing in restaurants all over Chicago, thanks in large part to chef-turned-purveyor Andrew Gietzen, whose year-old Preserved States imports hand-packed seafood directly from fisheries in Galicia (in Spain) and Porto (in Portugal). “All the stuff we are bringing in is put into a tin the same day as it’s caught, if not within hours,” Gietzen says.

Most local spots embrace the food’s unpretentiousness by offering it to the table still in the tin and with simple accompaniments. Cold Storage offers sardines with pieces of toast. Bar Biscay has served tinned baby squid with heirloom tomato gazpacho. Fahlstrom’s Fresh Fish Market will bring you cheeses, ham, and other goodies as part of an entire spread of conservas.

Want to bring some home? The specialty store Wixter Market and the liquor store Off Premise both carry several varieties of conservas. They’re not all that different from your familiar canned tuna — just better traveled.