Pat the short ribs dry, season with salt and pepper, and dust lightly with flour, shaking off excess.
Heat the neutral oil in a large heavy pot or Dutch oven over medium high heat. Sear the short ribs on all sides until deeply browned, working in batches. Remove and set aside.
Add the onion to the pot and cook until softened, about 2 minutes. Add the garlic and cook until fragrant, about 30 seconds.
Stir in the tomato paste and cook for a minute to deepen the flavor.
Add the beef broth, scraping up any browned bits from the bottom of the pot. Stir in the tomato sauce, shoyu, Worcestershire sauce, and bay leaves, then return the short ribs and any drippings to the pot. Bring to a boil, reduce to a low simmer, cover, and cook until the meat is tender and starting to pull from the bone, about 2 to 2 1/2 hours.
Add the carrots, potatoes, and celery. Continue simmering until the vegetables are fork tender, about 25 to 30 minutes.
Adjust seasoning with additional salt and pepper as needed. Serve hot with steamed white rice.