Remove the silver skin from the back ribs and cut into individual bone segments and place into a large mixing bowl. Add soy sauce, vinegar, and brown sugar. Mix well.
Add onion, garlic, peppercorn, bay leaves and ribs into the inner cooking pot of an electric pressure cooker.
Close and lock the lid, making sure the steam knob is on Sealing/Locked. Pressure cook on high for 15 minutes.
Once the cooking is done, quick release the pressure.
Press Sauté, adjust to high. Simmer for another 10 minutes until the sauce thickens and is reduced roughly by half, stirring occasionally.
Preheat the broiler. Line a sheet pan with aluminum foil. Lay the ribs down. Brush the ribs with the sauce. Broil for 3-5 minutes until the ribs are browned and caramelized.
Flip the ribs over and brush with more sauce. Broil for another 3-5 minutes until ribs are browned and caramelized.
Pour any remaining sauce over the ribs and serve with Jasmine rice.