In a heavy-bottomed Dutch oven, heat olive oil over medium-high heat. Season the short ribs with salt and pepper and sear them for about 4-5 minutes on each side until nicely browned. Remove the ribs and set aside.

In the same pot, add the chopped onion, carrots, and celery. Sauté for 5-7 minutes, or until the vegetables soften. Stir in the garlic and cook for another minute until fragrant.

Pour in the red wine and scrape up any browned bits from the bottom of the pot. Let it simmer for a few minutes to reduce the liquid slightly.

Stir in the beef broth, tomato paste, thyme, bay leaves, and return the seared short ribs to the pot. Bring everything to a gentle boil.

Reduce the heat to low, cover the Dutch oven, and simmer for 3-4 hours, or until the meat is tender and falling off the bone.

Once done, remove the short ribs and strain the sauce to separate the solids. You can blend the sauce with an immersion blender if you prefer a smoother texture. Adjust seasoning as necessary.