Prep the Tuna: Pat the tuna steaks dry with paper towels. Let them sit at room temperature for about 10 minutes—this helps them cook evenly.
Marinate the Tuna: Rub the marinade over both sides of the steaks. Let them rest for 5 minutes while your skillet heats.
Sear the Tuna: Gently lay the tuna steaks in the hot skillet. Sear for 2–3 minutes without moving them—this helps form a crust.
Flip and Finish: Turn the steaks using tongs. Sear the other side for 1–2 minutes for rare to medium-rare (internal temp 115–125°F). Add 1–2 more minutes for medium, if desired.
Rest and Serve: Remove the tuna from the skillet and let it rest for 2 minutes. Slice against the grain and garnish with lemon wedges and chopped parsley if using.