Hoisin sauce gives these burgers a juicy texture, while ginger and garlic provide a burst of flavor, and water chestnuts deliver an appealing crunch. Serve them over tender greens or on toasted whole-wheat buns.
To prepare burgers: Preheat grill to medium-high.
Place bread in a food processor and pulse into fine crumbs. Transfer to a large bowl. Add ground turkey, water chestnuts, hoisin, scallions, ginger, garlic and salt; mix well. (The mixture will be moist.) With dampened hands, form the mixture into four 1/2-inch-thick patties (see Tips).
Oil the grill rack (see Tips). Brush the patties with 1 1/2 teaspoons sesame oil. Grill until browned and no longer pink in the center, about 5 minutes per side. (An instant-read thermometer inserted in the center should register 165°F.)
To prepare sesame mayonnaise: Combine mayonnaise, yogurt, soy sauce and oil in a small bowl; whisk until blended. Serve the burgers with the mayonnaise.
Check labels carefully and select ground turkey breast. Regular ground turkey, which is a mixture of dark and white meat, has a higher fat content (similar to that of lean ground beef). Hoisin sauce is a thick, dark brown, spicy-sweet sauce made from soybeans and a complex mix of spices. Look for it in the Asian section of your supermarket. When forming burger patties, make them thinner at the center to prevent them from steaming as they cook. Oiling a grill rack before you grill foods helps ensure that the food won't stick. Oil a folded paper towel, hold it with tongs and rub it over the rack. (Do not use cooking spray on a hot grill.)