Prep the potatoes and carrots by cutting them into chunks about 1” to 1 1/4” in size. See notes. 

Combine 1 teaspoon of salt and the ground pepper in a small dish and set aside. Pat the beef dry with paper towels and season both sides with the salt and pepper.

Heat olive oil in a 10-inch skillet over medium-high heat. Brown one side of the roast for 3 to 5 minutes. Flip and brown the other side for 3-5 minutes until brown and crusty. For the outer edges of the roast, sear for 30 seconds to cook off the pink. Transfer the roast to a plate and turn off the skillet.

Pour the beef broth into the hot skillet and scrape up any bits of the roast cooked onto the bottom of the pan. Set aside.

Add the diced onions, potato chunks, carrot chunks, tomato paste, garlic, thyme, and bay leaves to the Crockpot. Sprinkle on 1/2 teaspoon salt. 

Nestle the roast into the Crockpot on top of the potatoes and carrots. Pour the juices from the plate into the Crockpot as well.

Next, pour the hot broth from the skillet over the roast and veggies.

Put the lid on the slow cooker and cook on LOW for 8-10 hours or on HIGH  for 4-6 hours. The roast is done when it pulls apart with very little resistance and reaches an internal temperature of 210°F.

Once the meat is cooked, fish out the bay leaves and transfer the pot roast to a cutting board. Cover loosely with foil, and let the meat rest for 20 minutes. 

To make the gravy, combine 1 cup of the cooking liquid and 3 tablespoons of cornstarch in a small bowl and whisk until smooth. Some lumps are ok. Add the cornstarch back to the Crockpot, cover, and cook on HIGH heat for 15-20 minutes until thickened.

Shred the meat with two forks, or if you want to cut slices, cut it against the grain. Give the gravy a taste before serving, and add the final ½ teaspoon of salt (if necessary) and more pepper to taste. Serve the meat on a platter with the veggies and pour a little gravy over the top. Serve extra sauce on the side.