Season the short ribs generously with salt and pepper.

Heat the oil in a heavy Dutch oven over medium-high heat and sear the short ribs on all sides until deeply browned, then remove to a plate.

Lower the heat to medium, add the onion and carrots, and cook until softened and starting to caramelize.

Add the garlic and tomato paste and cook for 1 minute until fragrant.

Pour in the red wine and scrape up any browned bits from the bottom of the pot. Simmer for 5 minutes.

Stir in the soy sauce, beef stock, brown sugar, bay leaves, and thyme.

Return the short ribs to the pot so they are mostly submerged. Cover and braise at 325°F for about 3 hours, until fork-tender.

Skim excess fat, stir in the vinegar, and adjust seasoning to taste.

Serve the short ribs with the reduced sauce spooned over the top, finished with scallions or parsley.