8 to 10sprigs fresh thymetied into a bundle with kitchen string
2tablespoonscornstarchmixed with 2 tablespoons water to create a slurry
¼cupfinely chopped fresh flat-leaf parsleyoptional for serving
For Serving
Mashed potatoes, cooked pappardelle or similar pasta, roasted potatoes, or creamy polenta
Instructions
Pat the short ribs dry, then season generously all over with 4 teaspoons salt and 1 teaspoon pepper.
Heat a large Dutch oven or similar large, sturdy-bottomed pot over medium-high heat (no need to add oil). Add half of the short ribs in a single layer, arranging them so that they do not touch. Sear all over until they are deeply browned on all sides, about 8 to 10 minutes per batch. Transfer the short ribs to a big baking dish that can catch any juices. Repeat with remaining short ribs.
Carefully discard all but about 2 tablespoons fat from the pot. Reduce the heat to medium and add the carrots, celery, onion, and remaining 1 teaspoon salt and ½ teaspoon pepper. Cook, stirring periodically, until the vegetables are tender and beginning to brown, about 12 minutes.
Move the vegetables over to one side of the pot to create some space. Add the tomato paste and stir continually for 30 seconds to bloom its flavors, then stir the paste into the vegetables to combine. Stir in the garlic and cook 30 seconds, just until fragrant.
Add the wine (be careful as it will splatter), and using a wooden spoon or sturdy spatula, scrape up any browned bits that have collected on the pan. Bring the wine to a boil, then reduce the heat to a simmer. Let simmer until the wine is reduced by approximately half, about 10 minutes.
Carefully transfer the mixture in the Dutch oven to a large slow cooker. Stir in the broth, diced tomatoes, and thyme bundle.
Nestle the short ribs into the pot, along with any cooking liquid that collected in the dish.
Slow cook short ribs in the crockpot on LOW, until they are fall-apart tender, 7 to 8 hours (don't cook on high—you really need that long, gentle cook time to render the fat).
With a slotted spoon, carefully remove the short ribs to a large plate (it's fine if you have some vegetables with the meat too). Check the pot for any bones that have separated from the meat and discard. Fish out and discard the thyme bundle.
Carefully transfer the cooking liquid to a large pot on the stove. Stir in the cornstarch slurry. Bring the liquid to a rapid simmer. Let cook until it is reduced, about 15 minutes (it won't be super thick but should reduce somewhat). If desired, skim off some of the fat with a spoon (you won't be able to get it all).
Serve the short ribs hot over mashed potatoes with the cooking juices spooned over the top. Garnish with fresh parsley.
Notes
TO STORE: Refrigerate leftover crockpot short ribs in an airtight storage container for up to 3 days.
TO REHEAT: Rewarm short ribs in a Dutch oven on the stovetop over medium-low heat or in the microwave.
TO FREEZE: Freeze short ribs in an airtight, freezer-safe storage container for up to 3 months. Let thaw overnight in the refrigerator before reheating.