- Using paper towels, blot meat dry, then sprinkle all over with salt and pepper. In a multicooker set to sauté high, warm 1 tablespoon oil. Add beef to pot, working in batches to avoid crowding. (You want the meat to sear and brown, not steam.) Let short ribs cook, undisturbed, until deeply browned on all sides, flipping with tongs, about 3 to 4 minutes per side. (When the meat is sufficiently seared, it will release from pot without tugging.) Transfer pieces to a large bowl and repeat with remaining meat, adding more oil as necessary. Reduce heat and add a few drops of water if browned glaze on bottom of pot begins to scorch between batches.
- Reduce heat to sauté medium and add onions and garlic. Stir well to scrape up browned bits and glaze from bottom of pot, adding a splash of water if necessary to loosen them. (The multicooker might issue a burn warning message if there are solids stuck to the bottom of the pot during pressure-cooking.) Cook, stirring often, until the onions begin to soften, about 3 minutes.
- Stir in cola, chili sauce, worcestershire, soy sauce, dried thyme, and paprika. Cook, stirring constantly, for 1 minute. Return beef to pot.
- Cover, and cook on high pressure for 55 minutes. Let stand for natural release of pressure.
- Use a slotted spoon to transfer meat to a bowl, leaving cooking liquid and vegetables in pot. Spoon off as much fat as possible from the surface or use a fat separator. Puree cooking liquid and vegetables with an immersion blender. (Alternatively, puree in batches in a blender, filling it no more than one-third full with hot liquid. Return puree to pot.)
- Stir in bourbon and season gravy with salt and pepper. Return ribs to pot, nestling them together and coating them with gravy. Set multicooker to warm medium and let meat rest in gravy for 20 minutes. Serve warm, sprinkled with fresh thyme.