Pat the chuck roast dry with paper towels, then generously season all over with salt, pepper, and chopped herbs.
Heat a cast iron skillet over high heat until shimmering, then add a little oil. Sear the roast on all sides until deeply browned and crusty—about 4-5 minutes per side. This locks in flavor and creates a beautiful crust.
Transfer the seared beef to the slow cooker and arrange sliced onion, carrots, and parsnips around it. Pour in the beef broth, red wine, and splash of soy sauce, ensuring the liquid covers the vegetables but not necessarily the meat.
Add the chopped garlic and herb sprigs on top of the roast. Cover the slow cooker with the lid and set to low.
Let the roast cook slowly for 8-10 hours, until the meat is fork-tender and easily shreds apart, filling the house with a savory aroma.
About an hour before the cooking time ends, remove the lid to allow the gravy to thicken slightly. Skim off excess fat if desired, and taste the sauce—adjust seasoning if needed.
Remove the roast from the slow cooker and let it rest on a cutting board for 15 minutes to allow juices to redistribute, making it easier to slice.
Slice the roast against the grain into thick, juicy pieces. Spoon the rich gravy and cooked vegetables over the slices.
Serve hot with crusty bread or your favorite sides, and enjoy the tender, flavorful holiday beef.