– Prepare the Slow Cooker: Place the sliced onions and minced garlic in the bottom of your slow cooker. – Sear the Beef: Season the chuck roast generously with salt and black pepper. In a large skillet, heat some oil over medium-high heat. Sear the roast on all sides until it’s nicely browned. Transfer it to the slow cooker on top of the onions and garlic. – Create the Au Jus: In the same skillet, deglaze with red wine (if using), scraping up any flavorful bits. Add beef broth, Worcestershire sauce, and dried thyme. Bring the mixture to a simmer. – Slow Cook to Perfection: Pour the simmering broth mixture over the beef in the slow cooker. Cover and cook on low for about 6-8 hours or until the beef is tender and easily shreds with a fork. – Shred and Assemble: Remove the beef from the slow cooker and shred it using two forks. Strain the au jus from the slow cooker into a serving container. – Toast and Serve: Split the French rolls or baguettes and, if desired, toast them in the oven. Pile the shredded beef onto the rolls, and add Swiss or provolone cheese slices, if you like. Serve with prepared horseradish or Dijon mustard for dipping.