Add the vinegar, sugar and 1 tablespoon of salt into the Cooking Vessel.
Select SEAR/SAUTE and set the time to 30 minutes. Press START.
Stir occasionally. Once the sugar and salt have dissolved, press CANCEL. Place the red onion in a medium bowl and pour the vinegar mixture over it. Let it cool at room temperature, then refrigerate (can keep up to 1 week while refrigerated) until ready to use. Wipe down the pot with a paper towel.
Season the pork roast with salt and pepper.
Select SEAR/SAUTE and set the time to 30 minutes. Press START. Add the oil. Once the oil starts to smoke, sear the pork until browned, about 2 minutes per side. Transfer to a plate.
Pour off all but a thin layer of fat from the Cooking Vessel and place the Cooking Vessel back into the Cooker Base.
Add the yellow onion and garlic into the Cooking Vessel and cook. Stir occasionally until they begin to soften, 1-2 minutes. Add the beer and stir to scrape the browned bits off the bottom. Add the chopped green chiles, cinnamon and chipotle chile. Stir well to combine.
Return the pork into the Cooking Vessel, add the broth and squeeze the juice out of the oranges and add the peels into the vessel.
Close the lid. Select - SLOW COOK and set the time to 4 hours . Press START.
Once the cooking cycle is complete, open the lid. Carefully transfer the pork to a cutting board and cover loosely with aluminum foil until ready to carve.
Skim the fat off the cooking liquid. Using a sharp knife and a fork, cut and shred the pork into bite-size pieces.
Arrange the meat on a platter and moisten lightly with the cooking liquid.
Serve right away with pickled red onion, tortilla, lime wedges and cilantro.