Season the chuck roast generously on all sides with salt and pepper.
Heat olive oil in a large skillet over medium-high heat and brown the roast for 3-4 minutes per side, then transfer to slow cooker.
Wash baby potatoes and place half of them in the bottom of the slow cooker, arranging the roast on top, then surround with remaining potatoes.
Whisk together beef broth, tomato paste, garlic, and thyme, then pour over the roast and potatoes.
Add bay leaves, cover, and cook on low for 8 hours or until roast is fork-tender.
Remove bay leaves, shred or slice the roast, and serve with the potatoes and cooking liquid spooned over top.