Cut the chuck roast into 6 large chunks and season lightly with salt and pepper.

(Optional) If your slow cooker has a sear function, use it to brown the roast chunks on two sides before cooking. If your slow cooker doesn’t have a sear function, you can do this step in a Dutch oven or skillet on the stove, or skip it entirely.

Add the onions, carrots, and all of the pot roast sauce ingredients to the slow cooker. Stir everything together, then nestle the beef chunks in.

Cover and cook on high for 5–6 hours or low for 8–9 hours, until the beef is tender and easily pulls apart.

(Optional) When the beef is done, remove it and the carrots (it’s okay if some are still left in the pot) from the slow cooker and set aside.

In a small bowl, whisk together the cornstarch and water to make a slurry.

If your slow cooker has a sear or sauté function, switch it on and stir the slurry into the sauce. Simmer for 5–10 minutes, until the sauce is slightly thickened. If not, pour the sauce into a skillet on the stove and simmer with the slurry until thickened, then return it all to the slow cooker.

Serve the shredded beef and carrots over warm white rice with plenty of sauce on top and sprinkle with diced green onions + sesame seeds.