A few secret ingredients make this crockpot beef stew the BEST EVER!
Cut the beef chuck roast into 1-2 inch cubes and set aside.
In the crockpot, put the halved baby carrots, sliced celery, fire-roasted diced tomatoes, tomato paste, dried parsley, dried thyme, bay leaf, Worcestershire sauce, and sugar in the bottom of a large (6 quart) crockpot.
Heat a large dutch oven on high (do not use a nonstick skillet). Add in 2 tablespoons olive oil. Once the dutch oven is hot, add the cubed beef. Sear beef for about 2 minutes on each side (to get a nice sear, don't stir the beef around. Leave it in one spot and then flip it to the other side after about 2 minutes using tongs). Do this in batches so you don't overcrowd the beef and get a nice sear. Remove the beef with a slotted spoon into a bowl. Add more oil to the batches as needed.
Do NOT wash out the dutch oven. Add the remaining 1 tablespoon of oil. Once the oil is hot, add in the diced onions. Cook for 3-4 minutes, scraping up the browned bits in the dutch oven as you stir the onions. Then add in the garlic and cook for another minute. Add in the butter and allow to melt. While whisking constantly, add in the flour and, whisking constantly, cook for one minute. Pour in the beef stock gradually, while whisking constantly. Simmer over low heat until thickened, about 2-3 minutes.
Pour this mixture into the crockpot and add the seared meat into the crockpot (drain off the juices that will have accumulated). Add in the beef gravy, salt and pepper to taste (I add about 1/2 teaspoon of each) and give everything a good stir. Make sure the beef is completely submerged in liquid.
Cover and cook on low for 9-10 hours (recommended) or high for 6-7 hours.
About 20 minutes prior to serving, bring a large pot of salted water to a boil and cook the miniature potato gnocchi according to package directions (~2-3 minutes). Drain and set aside.
Taste the stew and add additional seasonings if needed (salt, pepper, or a pinch of sugar goes a long way). Serve the stew in bowls with a few spoonfuls of gnocchi into each bowl*.
*I add the gnocchi to individual bowls so the leftovers don't get bloated.