Preheat oven to 300-degrees (F) (150 degrees Celsius).
Season the short ribs on both sides with salt and pepper.
Working in batches (if needed) brown the short ribs well on both sides in the avocado oil over medium/high heat. Remove the meat to a plate after browning.
Reduce the heat to medium. Add the chopped onion and bacon to the pot and cook, stirring occasionally, while the onion softens and the bacon cooks.
Scrape up the browned bits from the bottom of the pot while cooking the bacon and onion. If needed, add a splash of beef broth to help loosen the bits.
Add the short ribs and the bay leaves into the pot along with any accumulated meat juices leftover on the plate from browning the short ribs.
Meanwhile, in a small bowl, stir together the beef broth, horseradish, ketchup, and garlic.
Reduce the heat to low, and pour in the beef stock braising liquid along with the red wine.
Cover the pot and place into a preheated oven to braise for 4 hours.
Remove the pot from the oven. Taste the sauce, and season with additional salt and pepper, if desired.
Remove the bay leaves and serve the short ribs over mashed potatoes, noodles, rice, or polenta. Spoon the juice over the meat, and enjoy!