Preserving tuna is an ancient art, perfected by the Italians thousands of years ago. Even today, the finest canned tuna comes from Italy and Spain; what separates these cans of tuna from most of the varieties on the grocery store shelf is that they are preserved in olive oil instead of water.
Albacore is the primary species used in canned tuna. Commercial canners often steam their albacore, but a far more luxurious result is achieved thanks to a slow poach of the fish in olive oil. This is a process that the French call confit. It’s an easy process, that only requires a deep pan, thermometer, and a cheesecloth or a fine mesh. Your preserved tuna will then keep in the refrigerator for up to two weeks. If you’d like actually canned tuna, you must pressure-can it in a steam canner.
Use high-quality albacore or yellowfin tuna, or this recipe yields great results with other kinds of fish like mako shark, halibut, swordfish, or sturgeon.
This homemade canned tuna is great in recipes like tuna salad or this innovative pasta dish with tuna, but it’s best au naturel. Use it in a Nicoise salad, open-face sandwiches, flatbreads, or as your main protein alongside potatoes, rice, or quinoa.
With the help of a sharp knife, cut fish into large chunks about 1-inch thick. Generously sprinkle pieces of fish with salt on both sides.
In a deep saucepan, mix infused oil ingredients. Slowly heat oil mixture over medium heat until you begin to see a gentle simmer.
With the help of a food thermometer, check that the oil is close to 160 F. Hold this temperature for about 15 minutes and then turn off heat. Cover the pot and leave oil to cool off for approximately 45 minutes.
Once oil has cooled, turn heat back on to medium and heat it up again to 150 F. Once you’ve reached this temperature, slip in the fish and arrange pieces in one layer, so fish is completely covered in oil.
Turn off heat and cover pot again. Let fish steep in oil for another 30 to 45 minutes.
After fish has steeped in hot oil, use a slotted spoon to remove it and transfer it to clean plastic or glass container.
Let oil cool to room temperature, then strain through a piece of cheesecloth or fine mesh and pour it over fish. Make sure you do not include any liquid that the fish gave off during cooking. You want oil only to cover the fish. If your infused oil seems too contaminated with fish bits, use clean olive oil if needed. With just oil covering it, the fish will last in the refrigerator for two weeks.