Combine oxtail, onion, thyme, browning sauce, scallions, red pepper flakes, ginger, allspice, garlic, and bay leaves in a large bowl. Cover with plastic wrap and marinate in the refrigerator, 8 hours to overnight.
Heat a pressure cooker over medium-high heat. Add the beef. Cook, turning halfway, until juices are released and outsides are browned, about 10 minutes. Add 1 cup broth and water. Cover pot, lock the lid, and place pressure regulator over vent according to manufacturer's instructions. Reduce heat to low and simmer until mostly tender, about 2 1/2 hours.
Stir remaining beef broth and tomato paste into the beef. Cover with the lid and seal. Increase heat to high. Heat until steam escapes in a steady flow and makes a whistling sound, 7 to 10 minutes. Reduce heat to low and cook until oxtail is tender, 40 minutes to 1 hour.
Let pressure release naturally according to manufacturer's instructions, 5 to 10 minutes. Unlock lid and add beans, salt, and pepper. Increase heat to medium-high high; cook until flavors meld, about 5 minutes more.