Tuna Burgers with Wasabi Mayonnaise

INGREDIENTS

• 1 tablespoon unseasoned rice-wine vinegar
• Pinch of sugar
• 1/4 cup extra-virgin olive oil
• Coarse salt and freshly ground black pepper
• 1 pound sushi-grade tuna, very finely chopped
• 2 scallions, white and light green parts only, trimmed and minced
• 1 tablespoon soy sauce
• 1 tablespoon toasted sesame oil
• 1 teaspoon lemon zest
• Canola oil, for cooking
• 1/2 bunch arugula
• Wasabi Mayonnaise