Combine flour, salt and pepper and mix. Coat ribs well in the mixture.
Heat oil in a large skillet. Brown the short ribs on all sides. Work in batches and don't crowd the pan.
Transfer the short ribs to the slow cooker when they are browned.
Add the shallot, carrots, and celery to the skillet along with a ½ cup of water. Scrape up any bits left over from cooking the short ribs, and cook for approximately 5-10 minutes. The vegetables don't need to be fully cooked. Transfer to the slow cooker.
Add the remaining ingredients to the slow cooker (beef broth, bourbon, brown sugar, Worcestershire, garlic, and bay leaf). Cover and cook on low for 8 hours or high for 5 to 6 hours.
