All fully cooked fish flakes. Unlike other proteins, tuna flesh has little connective tissue, so it separates along its natural seems effortlessly. Any variety of tuna steak -- yellowfin, albacore and bluefin, for example -- work in any flaked preparation. Canned tuna undergoes high-pressure cooking that heats the flesh at around 250 degrees Fahrenheit, which alters its texture. Bulk tuna, or canned varieties that don't have a species on the label, cooked at that temperature tends to mash and tear instead of flake. For flaked canned tuna, use a quality white-albacore variety for meaty chunks that have a firm texture.
Cook the tuna steak until it reaches an internal temperature of 145 F and the flesh is opaque throughout. You can use any cooking method; steaming, pan-frying and roasting all work.
Let the tuna cool for a few minutes. Place the tuna steak in the center of a large plate or platter.
Insert two dinner forks in the steak and gently twist them to separate the flesh. The tuna will separate into 1/2- to 1-inch chunks; pull the chunks apart using the forks to break them down to the desired size.
Drain the canned tuna in a colander. If you want to rinse the salty brine off, run cold water over it for a few seconds and let it drain.
Transfer the tuna to a bowl or platter. Separate the tuna it chunks with your fingers; it will come apart with little effort.
Continue pulling the chunks apart until they reach the desired size. Pat the tuna with a paper towel to absorb excess moisture, if desired.