Tangy BBQ Sandwiches by Guest Chef Amy

1 boneless beef chuck roast (3 ½ - 4 lb.)
1 large onion, chopped
4 cloves garlic, finely chopped
½ cup packed brown sugar
2 tsp ground mustard
1 tsp chili powder
1 tsp paprika
1/3 cup vinegar
1/3 cup Worcestershire sauce
3 Tbsp lemon juice
1 ¾ cups ketchup
Oval shaped buns/hoagies

In slow cooker, mix all ingredients except buns. Cover; cook on low for 5 hours, stirring occasionally. To serve, fill buns with beef mixture.