Prepare the Wasabi Mayonnaise: In a small bowl, combine mayonnaise, soy sauce, and wasabi powder.

Mix well until all ingredients are thoroughly combined.

Cover the bowl with plastic wrap and refrigerate for at least 10 minutes to allow flavors to meld.

Prepare the Tuna Burgers: Using a knife, chop the tuna steaks until coarsely ground into small pieces.

In a medium-sized bowl, mix the chopped tuna with minced garlic, minced ginger, salt, and steak seasoning.

Divide the tuna mixture into 4 equal portions (approximately 5 ounces each).

Shape each portion into a patty about 1 inch thick.

Place the formed tuna patties in the refrigerator and chill for at least 15 minutes.

Preheat the grill to high heat (about 15 minutes). Ensure all burners are on high.

Oil the grill grate using a small wad of paper towels soaked in vegetable oil.

Grill the tuna burgers, covered, until browned on one side, about 3 minutes.

Flip the burgers carefully with a greased metal spatula.

Continue grilling, covered, to the desired level of doneness.

Cook for about 3 minutes for medium-rare, 4 minutes for medium, or 5 minutes for medium-well.

Be careful not to overcook the tuna burgers.

Serve the grilled tuna burgers immediately with the chilled wasabi mayonnaise.