Preheat sous vide bath to 170°F (76.7°C).
In a Dutch oven or other large pot or pan heat tallow or oil over medium-high heat.
Season short ribs liberally with salt and pepper.
Once the pan is hot, add short ribs in stages as to avoid crowding the pan and sear just until deeply browned on one side. Set aside.
Once all the short ribs are seared and set aside, add red wine to pan. Allow to cook until alcohol smell has dissipated, scraping the bottom of the pot with a wooden spoon to loosen any stuck on bits.
Bag ribs with reduced wine and pan drippings, seal and cook for 24-30 hours at 170°F (76.7°C). Once cooked, remove ribs from bag. Remove ribs from the bones and shred. Set aside.
In a food processor combine carrots, celery, onion and shallots. Process until mixture is very finely minced.
In a Dutch oven over medium heat, add oil, processed vegetable mixture, and garlic. Cook, stirring frequently, until vegetables are softened and reduced, 10-15 minutes.
Add the flour and tomato paste and stir until fully combined. Allow to cook for 2-3 minutes, stirring frequently.
Add the red wine and allow to cook until reduced by half, 10 - 15 minutes, stirring frequently.
Add the bay leaf, rosemary, thyme, beef broth and shredded sous vide short ribs. Allow to cook over medium-high heat, stirring frequently, until sauce thickens and ribs shred further into the sauce, about 20 minutes. Season sauce to taste with salt and pepper.
Serve over pasta or gnocchi and top with grated cheese and basil.
