Beef Burgers with Caramelized Onions

Ingredients:

4 medium onions, sliced

2 teaspoons granulated sugar

2 teaspoons olive oil

1/4 cup water

2 teaspoons balsamic vinegar

3/4 teaspoon salt, divided

1 pound extra-lean ground beef

2 tablespoons tomato paste

1/4 cup chopped fresh parsley

1/4 teaspoon ground pepper

4 hamburger buns, toasted

4 tomato slices

Directions:

Cook onion and sugar in hot oil in a large nonstick skillet over low heat, stirring often, 20 to 25 minutes or until onion is caramel colored. Stir in cup water, vinegar, and 1/4 teaspoon salt. Set mixture aside, but keep warm.

Combine ground beef, tomato paste, parsley, remaining 1/2 teaspoon salt, and pepper; shape into 4 patties.

Grill, covered with grill lid, over medium-high heat (350 to 400 degrees) 4 to 5 minutes on each side or until no longer pink.

Serve on toasted buns with caramelized onions and tomato slices.