Begin by liberally seasoning the bone-in beef short ribs with salt and pepper. Make sure every side is well-coated to enhance the natural beef flavors.

In a large skillet, heat a tablespoon of oil over medium heat. Once the oil is hot, add the seasoned short ribs and sear each side for about 3-5 minutes until they develop a golden-brown crust.

While the ribs are searing, chop your baby carrots, slice the mushrooms, and mince the garlic. Layer the carrots, mushrooms, and garlic at the bottom of the crockpot.

Carefully transfer the seared short ribs to the crockpot, placing them atop the vegetables. In a separate bowl, mix the beef broth, red wine, and tomato paste together, then pour over the ribs.

Add the unsalted butter, bay leaf, and fresh thyme on top of the ribs in the crockpot. Make sure the ribs are mostly submerged in the liquid for optimal cooking.

Cover your crockpot and set it to low heat. Allow the ribs to cook for approximately 8 hours until the meat is fork-tender.

Once beautifully tender, carefully remove the ribs and vegetables from the crockpot. Discard the bay leaf and thyme sprigs, then serve the short ribs with your choice of side.