• Slice 1 pound of sashimi-grade Ahi tuna into 1-inch pieces (about 5 pieces).
• In a saucepan, combine olive oil, 6 sprigs of fresh thyme, 3 crushed garlic cloves, 2 sprigs of fresh marjoram (optional), zest of 1 lemon (peeled with a vegetable peeler, without the white pith), 1/2 teaspoon whole black peppercorns, and 1/4 teaspoon red pepper flakes.
• Gradually warm the mixture on the stovetop over low heat to 150°F for about 8-10 minutes (check with a kitchen thermometer).
• Season the sliced tuna with kosher salt and freshly ground black pepper.
• Add the tuna to the saucepan, maintaining the oil temperature around 130°F. Cook for approximately 10 minutes until the tuna is just opaque throughout.
• Allow the tuna to cool in the infused oil.
• Serve the Tuna Conserva on a bed of salad, on pasta, or between slices of toasted hearty bread.
• Just before serving, season the Tuna Conserva with flaky sea salt and a few grinds of pepper.
• Transfer any leftover tuna, oil, and herbs to a bowl, cover tightly, and refrigerate. The Tuna Conserva will keep well for at least 4 days.

Optional American Twist

• Consider adding a pinch of smoked paprika or a few drops of hickory liquid smoke to infuse a subtle barbecue essence into the oil for an American twist.