A classic burger should be rich and juicy with a big beefy flavor. Ground beef chuck is the benchmark for a great burger, but its also particularly high in saturated fat. We knew that a leaner meat was needed for a healthy makeover, so we chose lean ground turkey it's low-fat and easy to find. The drawback to using ground turkey is that you have to cook the burger all the way through and theres not a lot of fat to keep the burger moist. We tried adding yogurt, ricotta, miso and cottage cheese to compensate for the lost fat, but none of these substitutions resulted in the rich flavor we craved the turkey burgers were too tart, cheesy or meatloaf-like. We finally succeeded with the following adjustments:
Adding a small proportion of lean beef sirloin to restore the meaty flavor and moisture.
Adding a little balsamic vinegar for sweetness and Worcestershire sauce for flavor.
Serving it on a whole wheat bun, topped with caramelized onions.