Pre-heat oven to 350 degrees.
Season short ribs on all sides with salt and pepper.
Heat 3 tbsp oil in a dutch oven. As soon as oil starts to smoke, add the short rib pieces.
Brown them on medium well on all sides. Do not overcrowd them as you want them to brown, not steam. Once all sides are nicely browned, remove them and set aside.
In the same dutch oven, add the onions. Cook them for 2 minute stirring constantly. Add the gralic and cook for 30 seconds stirring constantly.
Pour in Dr. Pepper and deglaze Use a wooden spoon to scrape all the bits of goodness off the bottom of the dutch oven.
Add beef stock and tomato paste, combine well.
Return short ribs to dutch oven, cover and place in oven. Cook in oven for two hours until fork tender.
Remove short ribs from bone, shred with a fork, and serve with warm tortillas, salsa, thinly sliced radishes, chopped onion, cilantro.
