Ever wonder how they make canned tuna? Preserved tuna is an ancient art, perfected by the Italians thousands of years ago. Even today, the finest canned tuna comes from Italy and Spain. Commercial canners often steam their albacore -- which is the primary species used in canned tuna -- but you will get a far more luxurious result if you slowly poach it in olive oil, a process the French call confit.
First start with high-quality albacore or yellowfin tuna. You can do this with other kinds of tuna, too, and mako shark, halibut, swordfish or sturgeon also work very well. Cut the fish into large chunks about an inch thick, then salt them well.