Preheat oven to 300°F.
Remove the short ribs from the fridge, sprinkle liberally on all sides with salt.
Allow to sit at room temperature for about 15 minutes while you begin cooking the dish.
Add the bacon to a large Dutch oven over medium heat. Cook until the bacon becomes crispy.
Remove bacon with a slotted spoon, add to a plate covered with paper towels.
Pour off most of the bacon grease leaving only about 2 tablespoons still in the pot.
Return to heat, add the onions. Cook over medium high heat until starting to brown, about 8 minutes. Remove the onions with a slotted spoon, add to the pile of bacon.
Sprinkle the ribs on all sides with flour, rub to coat.
Increase the heat to high, add the ribs, searing until browned on all sides.
Pour off most of the fat that has accumulated.
Pour in the beer, scraping to deglaze the pan. Stir in the tomato past and the herbs.
Add the onions and the bacon back into the pot.
Cover and add to the oven, cook until the ribs fall off the bone and the meat is fork tender, 3 to 4 hours.
Remove the ribs, shred using too forks. Discard the bones and any large pieces of fat.
Return the meat to the pot, stir into the sauce (this helps the meat to be more flavorful and juicy).
Scoop the meat into a serving dish.
Serve with tortillas, onions and cilantro.