To make BBQ sauce: Stir together tomato sauce, brown sugar, mustard, vinegar, onion, chili powder and garlic in small saucepan. Bring to a boil. Reduce heat to low and simmer 5 minutes, stirring occasionally. Remove from heat; set aside.
To make chili: Heat oil in large saucepan over medium-high heat. Add pork; cook 5 minutes or until brown on all sides, stirring occasionally. Remove from saucepan; set aside.
Add onion and salt to same saucepan. Cook 4 minutes or until onion is tender, stirring occasionally. Stir in prepared BBQ, browned pork, undrained tomatoes, black beans, kidney beans and broth. Bring a boil. Cover, reduce heat and simmer 10 minutes or until pork is tender, stirring occasionally. Top each serving with sour cream, parsley and serve with warm cornbread, if desired.