Season the chuck roast with salt, pepper, garlic powder, and onion powder.
Heat olive oil in a large skillet over medium-high heat. Sear the roast on all sides until browned, about 3-4 minutes per side.
Place the potatoes, carrots, and onion in the bottom of a slow cooker.
Place the seared roast on top of the vegetables.
In a bowl, whisk together beef broth, Worcestershire sauce, and tomato paste. Pour over the roast.
Add thyme sprigs and bay leaves.
Cover and cook on low for 8-10 hours or on high for 5-6 hours, until the meat is fork-tender.
Remove the roast and vegetables from the slow cooker. Let the roast rest for 10 minutes before slicing.
Optional: For a thicker gravy, mix 2 tablespoons of cornstarch with 1/4 cup of cold water and stir into the cooking liquid. Cook on high for 15-20 minutes until thickened.
Serve the roast and vegetables with the gravy.
Notes
Searing the roast before slow cooking adds depth of flavor.
For a richer gravy, use red wine instead of some of the beef broth.
Leftovers can be stored in an airtight container in the refrigerator for up to 3 days.