Pat the roast dry and season it thoroughly with kosher salt and black pepper. Dredge the meat in flour, shaking off any excess. Heat canola oil in a large skillet over medium-high heat and sear the roast on all sides until nicely browned. Transfer the seared roast into the slow cooker. In the same skillet, add the chopped onion, dried oregano, sage, and thyme, stirring for about 2 minutes until fragrant. Pour in the red wine and scrape up any browned bits from the bottom of the skillet. Pour the wine mixture along with the beef stock into the slow cooker with the roast. Add the bay leaves. Cover and cook on low for about 8 hours until the beef is tender. About midway through cooking, add the chopped Yukon gold potatoes, carrots, and parsnips to the slow cooker. Continue cooking until the vegetables are soft and flavors meld perfectly. Once done, remove the bay leaves and shred or slice the meat to serve along with the braised root vegetables and rich sauce.