Once on a small, remote Pacific island, we ordered fishburgers for lunch. We didn't learn until later that the chef who put the sandwich on the menu had quit the day before, leaving an untrained cook in charge of the kitchen. After a long delay, while the staff pondered our order no doubt, the cheery waitress returned with two plates of bulging buns. Curious about the catch of the day inside, we lifted the lid to discover a regular hamburger pattie covered in a pile of canned tuna—truly a fishy fishburger. No one would make that mistake on the Big Island of Hawaii, where they treat fresh tuna as the prize among Neptune's treasures.
SERVES 4
| 6 | tablespoons Enriched Mayonnaise ([>]) or other mayonnaise |
| 1 | heaping teaspoon hot Chinese mustard or 1 tablespoon Dijon mustard |
| 2 | garlic cloves, roasted (see Technique Tip, [>]) and mashed |
| 1½ | pounds fresh tuna steak |
| 1½ | tablespoons extra-virgin olive oil |
| 2 | teaspoons hot Chinese mustard or 1½ tablespoons Dijon mustard |
| 2 | garlic cloves, minced |
BIG ISLAND DRY RUB
| 2 | teaspoons kosher salt or other coarse salt |
| 2 | teaspoons fresh-ground black pepper |
| 2 | teaspoons paprika |
| ⅛ | teaspoon dried ginger |
| 8 | slices sourdough bread |
| Crisp romaine leaves |
Prepare the mustard-garlic mayonnaise, combining the ingredients in a small bowl.
With a large, sharp knife, coarsely chop the tuna into ¼-inch cubes. Hand chopping is more work than chopping in a food processor, but the texture will be far superior. Transfer the tuna to a medium bowl and toss it with oil, mustard, and garlic.
Fire up the grill, bringing the temperature to medium (4 to 5 seconds with the hand test). While whole tuna steaks can handle high heat, the chopped burger mixture stays juicier over a lower fire.
Gently form the tuna mixture into four patties about ½ to ¾ inch thick. The patties should hold together firmly, but don't compact them or handle them any longer than necessary.
Prepare the dry rub, combining the ingredients in a small bowl. Sprinkle the rub equally over both sides of the burgers, lightly patting in the spices.
Transfer the burgers to a well-oiled grate. Grill the burgers uncovered over medium heat for 3 to 4 minutes per side, until lightly browned with medium-rare centers. If grilling covered, cook for 6 to 7 minutes, turning once midway. Toast the bread at the edge of the grill if you wish.
Spread the mayo on the bread and These fishburgers pair especially well add the burgers and romaine. Serve hot. with Grant Street Pickled Vegetables.