Fresh ahi tuna steaks are a nutritious, delicious entree you can whip up with only minimal effort and minutes of cooking time. The U.S. Food and Drug Administration recommends cooking ahi to 145 degrees Fahrenheit at its center, with its flesh flaky and opaque all the way through. However, it's standard to serve ahi -- which has meat that very quickly dries out -- rare or medium-rare, when it's still mostly pink inside. Pan searing, grilling and baking all work well for this fish.
The Prep Work
Marinate or season the fresh ahi. To marinate it, combine equal parts cooking oil and soy sauce, teriyaki sauce, wine, cider vinegar, lemon or lime juice or another suitable liquid. Soak the tuna steak in a nonreactive dish for 15 to 30 minutes. Alternatively, to simply season the fish, pat it dry with paper towels, brush both sides with cooking oil or melted unsalted butter, then pat on salt and pepper, along with other desired herbs, spices and aromatics, including: thyme, rosemary, oregano, dill, tarragon, sage, garlic or onion powder, coriander, allspice, curry powder, ginger and citrus fruit zest.
Into the Pan
Pan-searing is a quick way to turn out a delicious ahi tuna steak. Heat a heavy-bottomed skillet over a medium-high burner and wait for it to become hot enough that drops of water sizzle and evaporate as soon as they hit the surface. Add a small amount of cooking oil and let it heat to a watery consistency. Place the fish in the pan and cook a 1-inch thick steak for about 2 to 4 minutes per side, depending on how well-done you want it.
Onto the Grill
Grilling is another fast method for getting a tuna steak with a nicely browned exterior and a succulent interior. Preheat the grill to medium-high. Scrape the grill clean and grease it with cooking oil or nonstick spray so your fish doesn't pick up "off" flavors or stick. Cook a 1-inch thick steak for around 2 to 4 minutes per side, depending on the desired doneness. Leave it in place so the grill marks sear prominently into the flesh. If the tuna sticks to a well-oiled grill, it's just too soon to flip or take it off; the sear hasn't completed.
Into the Oven
If you prefer a hands-off cooking method and aren't too concerned about having a well-browned exterior and fast turnout, bake your fresh ahi. Preheat the oven to 450 F for at least 20 minutes and oil a sheet of aluminum foil. Wrap the marinated or seasoned tuna steak in the foil, sealing it securely but leaving a little space above the fish for air circulation. This steams the fish as it bakes, enriching its surface flavors and helping preserve its natural moisture. Cook a 1-inch thick tuna steak for about 6 to 15 minutes in the oven, depending on how cooked through you want it.