Simple and quick to grill, it is a winner everytime!
The Hawaiian's call their tuna: 'ahi.
This sandwich has been inspired by my visit to the Diamond Head Market & Grill in Waikiki, Oahu, Hawaii, in August 2007.
After climbing the 232 metre volcanic crater I had worked up quite an appetite, which I sated at this roadside eatery on the walk back to my hotel. Yummy!
Every time I grill this at home, it takes me back to paradise!
This sandwich is very simple to create, and has always attracted rave reviews when served to family and friends.
Created by Steve: SBDESIGNS
Step 1: Ingredients
Cooking Time: 5mins
Ingredients (Per Person):
100g TUNA Steak (see Note )
Olive/Canola/Cooking OIL (Spray cans are good)
Hamburger BUN, halved
Handful shredded LETTUCE
1/8 ONION, sliced, halved
1 teaspoon SOY SAUCE (SHOYU)
2 heaped teaspoon MAYONNAISE
WASABI to taste (see Note )
Note : Buy top quality Tuna steak if possible (sashimi quality is the best). It often comes in
2.5cm / 1" thick 200g steaks, so butterfly and then separate completely into individual
100g 1.25cm / 1/2" steaks.
Note : I buy wasabi (hot Japanese Horseradish sauce) in prepared tubes that I keep in the
refrigerator. Only a 1-2cm (3/8 - 3/4") squirt is sufficient per person.
Step 2: Cooking Instructions 
1. Heat BBQ to HOT.
2. Combine the wasabi and mayonnaise in a small dish, set aside.
3. Split the bun and butter the insides. Ensure that all components are beside the BBQ and
ready before commencing cooking, due to short cooking time.
Step 3: Cooking Instructions 
further 1/2 teaspoon soy sauce (shoyu).
5. Whilst onions are cooking, place bun halves face down on BBQ until toasted.
6. Remove and spread bottom half of bun with wasabi mayonnaise.
7. Top with shredded lettuce.
Step 4: Cooking Instructions 
around 45secs each side according to desire (see Note ).
9. Remove and gently place onto the bottom half of bun.
10. Top with marinated onions, cover with the top of bun.
11. Enjoy. Use toothpicks and cut in half for presentation, if desired.
Simply serve on its' own for a light lunch,
or for a larger meal: with a light salad, potato wedges, or both
Note : In cooking tuna, treat it like the 'steak of the sea' and cook to medium-rare, the heat left
in the fish will continue to cook to medium whilst you are eating it.
Step 5: Variations
(1) THAI SWEET CHILLI SAUCE instead of wasabi in the mayonnaise.
(2) Place a slice of TASTY CHEESE on tuna after the first turn.
(3) Add sliced TOMATO along with the lettuce.
(4) Pre-marinate tuna in GINGER-SOY or TERYAKI marinade.
(5) Add a PINEAPPLE ring (grilled also, if preferred).
I hope you enjoy my creation! Let me know your thoughts, Steve (SBDESIGNS).
P.S.: My mate calls it the ikiki Beach Burger (Watch the movie: Spirit of 76).