Directions

1. Combine the zest, juice, anchovies, garlic, and herbs in a dish. Add the tuna, turn to coat, and marinate for 15 minutes at room temperature or 1 hour in the refrigerator.
2. Prepare a ridged cast-iron stove-top griddle or outdoor grill. Salt and pepper the tuna and grill until well browned but still rare, about 2 minutes per side; the flesh will be firm and tight. For medium rare, cook 1 minute more, until the flesh begins to pull apart. For medium, cook 2 minutes more, until the flesh flakes apart. Remove to a cutting board to rest.
3. Meanwhile, bring the marinade to a boil. Arrange the tuna on dinner plates and spoon 2 tablespoons of marinade over each piece.