Preheat your oven to 275°F (135°C). Season the chuck roast with salt and pepper, and prepare your vegetables by cutting them.

In a large skillet, heat oil over medium-high heat. Sear the roast for 3-4 minutes per side until browned, then transfer to a slow cooker.

Add potatoes and carrots to the pot, forming a layer underneath the roast.

Sprinkle garlic and onion over the roast, add thyme, and pour in beef broth.

Cover tightly and cook for 4-6 hours or until the meat is tender.

Let the roast rest for 10 minutes before slicing and serve with vegetables.