Preheat the broiler and arrange an oven rack about 6 inches below the heating element. Line a large baking sheet with foil.
Season the short ribs with salt and pepper on both sides. Place the short ribs bone-side-up on the prepared baking sheet and broil for 5 minutes. Flip them over and broil for 5 additional minutes.
Meanwhile, add the pear, soy sauce, garlic, scallions, ginger, vinegar and fish sauce to a blender or food processor and puree until completely smooth, about 1 minute.
Spray a 6-quart slow cooker with non-stick cooking spray. Pour the pear puree into the bottom of the slow cooker. Stir in the chicken broth and tapioca to combine. Nestle the short ribs into the slow cooker (I set them on their sides so they could all fit in a single layer). Cover and cook on low for 9 to 11 hours.
Remove the short ribs from the slow cooker, place on a serving platter and tent with foil. Allow the liquid in the slow cooker settle for 5 minutes, then skim off the fat with a large spoon. Season with salt and pepper and stir in the cilantro. Pour 1 cup of the sauce over the short ribs and serve with the remaining sauce.
Note: If you are following a paleo or Whole30 eating plan, the following substitutions will make this recipe compliant >> Use coconut aminos instead of soy sauce, apple cider vinegar in place of rice vinegar and use Red Boat fish sauce, which does not contain sugar.Nutritional values are based on one serving