Preheat oven to 350F.

Salt and pepper the short ribs on both sides.

In a large Dutch oven, heat the canola oil over high heat.

Add the short ribs to the Dutch oven and brown well, turning once.

Once the ribs are browned well on both sides, remove from the Dutch oven and set aside.

Place the bacon into the Dutch oven and quickly brown, then remove and set aside with the beef.

Add the onion to the Dutch oven and cook over high heat until translucent. Add the garlic, carrots, and celery and continue to cook for around 3-5 minutes, or until the garlic becomes fragrant.

Keeping the heat up to high, add the beef broth, Guinness, and Marsala to the Dutch oven and deglaze it, bringing the liquid to a simmer and scraping up the browned bits from the bottom of the pot.

Place the ribs, bacon, thyme, rosemary, and vegetables into the Dutch oven, place the lid on the pan, and place it into the oven.

Cook at 300F for at least 2-3 hours, until the meat is tender and falling off the bone.

Let the meat cool slightly, then remove it from the pan and place into a large bowl. Using two forks, shred the ribs off the bone and into small pieces, removing the bones while you do this.

Skim the fat off the top of the braising liquid. At this point, you can then pour the liquid into a container and place in the freezer for about 30 minutes until the fat rises to the top and can be skimmed off easily.

Serve the shredded meat in corn tortillas and garnish with cilantro, queso fresco, avocado, pickled onion, and whatever other stuff you like to put on tacos!