This simple-to-make meal is a healthy and delicious variation on the traditional burger recipe.
Place vinegar and sugar in small bowl. Slowly whisk in 2 tablespoons olive oil to form an emulsion; season with salt and pepper; set aside.
Place tuna, scallions, soy, 2 tablespoons olive oil, sesame oil, and lemon zest in a large bowl; season with salt and pepper. Mix well, using your hands, to combine. Divide tuna mixture into six equal portions and form each portion into a 1/2-inch thick patty.
Place a large nonstick skillet over medium heat and add enough canola oil to coat bottom of skillet. Add patties, and cook until medium-rare, 2 to 3 minutes per side.
Place arugula in a large bowl, drizzle with reserved dressing, and toss to combine. Divide arugula evenly between 6 plates. Place one patty on each bed of arugula; serve immediately with wasabi mayonnaise.