Sloppy Joe Burgers

From The Great Big Burger Book. No one is absolutely sure who created this delicious sandwich but some believe the claim that the Sloppy Joe began in a Sioux City, Iowa, cafe as a "loose meat sandwich" in 1930, the creation of a cook named Joe.

• Ready In: 1 hr 57 mins
• Serves: 8-10

Ingredients

• 2  tablespoons olive oil
• 1  large onion, finely chopped
• 1  large carrot, minced
• 1  celery, minced
• 6  garlic cloves, minced
• 1⁄2 cup tomato paste
• 2 1⁄2 cups tomato puree
• 3  tablespoons cider vinegar
• 1⁄4 cup molasses
• 3  tablespoons Worcestershire sauce
• 2  lbs  ground round
•  hamburger bun

Directions

1. Let a large skillet get heated over medium heat; add in the oil; then add in the onion, carrot, celery, and garlic; stir/saute 5-7 minutes or until softened.
2. Stir in the tomato paste, tomato puree, vinegar, molasses, and Worcestershire sauce; bring to a simmer.
3. Lower heat to low and let simmer gently for 45-60 minutes or until thickened and the flavors have melded.
4. Add in a little water if the sauce gets too thick or dry.
5. In another large skillet over med-high heat, brown the ground beef, breaking the meat apart into small pieces; cook until the meat is no longer pink; drain.
6. Add the sauce to the meat and simmer over med-low for at least 10 minutes or until the flavors blend.
7. Serve by spooning ½ cup of the filling over half a toasted hamburger bun and topping with the other half.