Step 1: Prepare the Arm Roast

1. Season the Roast: Pat the arm roast dry with paper towels. In a small bowl, mix the salt, black pepper, garlic powder, onion powder, paprika, thyme, and rosemary. Rub the seasoning mixture evenly over the entire surface of the roast.
2. Sear the Roast: Heat the olive oil in a large Dutch oven or heavy-bottomed pot over medium-high heat. Sear the roast on all sides until browned, about 3-4 minutes per side. This step locks in the juices and adds depth of flavor.

Step 2: Prepare the Cooking Liquid

1. Deglaze the Pot: Remove the roast from the pot and set it aside. Add the minced garlic and sliced onion to the pot, sautéing for 2-3 minutes until fragrant. Pour in the beef broth and red wine (if using), scraping the bottom of the pot to release any browned bits.
2. Add Worcestershire Sauce: Stir in the Worcestershire sauce for an extra layer of umami flavor.

Step 3: Slow Cook the Roast

1. Return the Roast: Place the seared roast back into the pot, ensuring it’s submerged in the cooking liquid.
2. Add Vegetables: Arrange the carrots, celery, and potatoes around the roast.
3. Cover and Cook: Cover the pot with a lid and reduce the heat to low. Let the roast simmer for 2.5-3 hours, or until the meat is fork-tender. Alternatively, you can transfer everything to a slow cooker and cook on low for 6-8 hours.

Step 4: Rest and Serve

1. Rest the Roast: Once cooked, remove the roast from the pot and let it rest for 10-15 minutes. This allows the juices to redistribute, ensuring a moist and flavorful result.
2. Slice and Serve: Slice the roast against the grain and serve with the cooked vegetables and a ladle of the rich cooking liquid.