2 tablespoons olive oil
2 red onions, sliced into 1/4-inch thick rings
2 tablespoons granulated sugar
4 tablespoons red wine vinegar
1 pound ground turkey
1 large egg, beaten
1 tablespoon Worcestershire sauce
1/2 teaspoon crushed dried sage
1/2 teaspoon salt
1/4 teaspoon ground black pepper
4 hamburger buns
Heat a large nonstick skillet over medium-high heat. When hot add oil and sauté onions until slightly softened, about 2 minutes. Lower heat to medium-low and add sugar; cook, stirring frequently for 3 more minutes. Add vinegar and stir well. Cover and simmer for 15 minutes, or until onions are soft and dark golden brown. Remove from pan and hold warm.
While onions are cooking, combine turkey, beaten egg, Worcestershire sauce, sage, salt and pepper in a large bowl; mix gently to blend. Form into 4 patties.
In the same pan the onions were in, cook patties over medium-high heat until golden brown on both sides and cooked until no longer pink inside, about 8 minutes. Add oil if necessary.
Serve turkey burgers on buns topped with caramelized onions and desired condiments.
Makes 4 servings.