Directions

1. 1

   Place the beef roast in a large pot or Dutch oven. Add the diced onion and enough water to partially submerge the meat. Cover and bring to a boil over medium-high heat, then reduce to medium-low. Simmer for 4 to 5 hours, or until the beef is very tender and shreds easily with a fork. Check occasionally and add water as needed to keep the meat from drying out.

2. 2

   Once the beef is fully cooked and tender, remove it from the broth and place on a cutting board. Using two forks or your hands, shred the beef into bite-sized pieces. Set aside.

3. 3

   In a small bowl, whisk together the cornstarch and water until smooth, with no lumps.

4. 4

   In the pot with the remaining broth, combine the ketchup, cola soda, Dijon mustard, and Worcestershire sauce. Stir well over medium heat until the mixture is warm and the flavors are incorporated.

5. 5

   Slowly pour the cornstarch slurry into the sauce while stirring constantly. Continue cooking for 2 to 3 minutes, stirring often, until the sauce thickens and coats the back of a spoon without running off immediately.

6. 6

   Return the shredded beef to the pot and stir until every piece is coated with the sauce. Simmer for an additional 10 minutes on medium-low heat, stirring occasionally, to allow the flavors to meld.

7. 7

   Divide the barbecue beef evenly among the sandwich buns and serve immediately. Add extra sauce to each sandwich as desired.