Preheat oven to 350 degrees.
Cut the chuck roast into 3 inch pieces. Season with salt and pepper.
Heat the avocado oil over medium/high heat in a large stock pot.
Sear the roast on all sides, then remove and set aside. You may need to work in batches.
Add the tomato paste and beef broth. Stir and make sure to scrape any bits on the bottom of the pan.
Add the onions and celery and garlic.
Add the meat back in and season with the pot roast seasoning.
Stir slightly being careful to leave the veggies on the bottom.
Bake for 2 hours with the lid on
Remove from the oven and add in the carrots. I used a fork to gently push them all under the liquid just enough.
You do not need to add any more seasoning at this point.
Put the lid on, return to the oven and cook for about 2 more hours. It is done when the meat is fork tender and it has reached an internal temp of 195 degrees.
The liquid should be thick enough already to use as a gravy, but you can thicken with a corn starch slurry.