Created by TeresaS on October 17, 2015
Step 1: Cook bacon in pressure-cooker pot over medium-high heat until browned and crisp, about 3 minutes. Stir in onion and cook until softened, about 5 minutes. Stir in garlic and cook until fragrant, about 30 seconds. Stir in pomegranate juice, brown sugar, orange zest, juice, and thyme. Using wooden spoon, scrap up all browned bits stuck on bottom of pot. Pat short ribs dry with paper towels, season with salt and pepper, and nestle into pot.
Step 2: Lock pressure-cooker lid in place and bring to high pressure over medium-high heat. As soon as pot reaches high pressure reduce heat to medium-low and cook for 35 minutes, adjusting heat as needed to maintain high pressure.
Step 3: Remove pot from heat and allow pressure to release naturally for 15 minutes. Quick release any remaining pressure, then carefully remove lid, allowing steam to escape away from you.
Step 4: Transfer short ribs to platter, tent loosely with aluminum foil, and let rest while finishing sauce. Strain sauce into fat separator, let sit 5 minutes, then pour defatted sauce back into now-empty pot. Whisk vinegar and cornstarch together, then whisk into sauce and simmer over medium heat until thickened and measures 1 1/2 cups, about 15 minutes. Off heat, whisk in butter and season with salt and pepper to taste. Serve sauce with ribs.