SEASON: the roast. Sprinkle 1 teaspoon onion powder, 1 teaspoon garlic powder, and ½ teaspoon black pepper evenly over the 5 pound chuck roast and rub to coat.
SEAR: the roast. Heat 1 tablespoon vegetable oil in a large cast iron skillet over high heat. Sear the roast on all sides until browned. Transfer to a 6 to 7 quart slow cooker.
ADD: the garlic cloves by tucking them into natural crevices or seams of fat. Add carrots around the roast if using.
POUR: in 1 ½ cups beef stock, ⅓ cup pepperoncini juice, and 2 tablespoons soy sauce. STIR in 3 tablespoons dry minced onion, 1 tablespoon beef bouillon powder, 2 teaspoons dried parsley, 1 teaspoon dried chives, 1 teaspoon dried dill, ½ teaspoon dried oregano, and 1 bay leaf. Add 6 whole pepperoncini.
COOK: on low for 8 to 10 hours, or on high for 4 to 6 hours, until the roast is very tender and pulls apart easily.
SHRED: lightly. Use tongs to break the roast into large pieces. Cook on low for 30 minutes so the meat absorbs the juices. Remove the roast to a cutting board and shred fully.
PREPARE: the gravy. Melt ¼ cup unsalted butter in a saucepan over medium heat. Whisk in ¼ cup flour to make a roux. Cook 1 to 2 minutes until lightly golden. Slowly whisk in 2 cups hot beef juices from the slow cooker. Simmer until thickened. Add a splash of stock if needed to thin.
SERVE: the shredded pot roast with gravy over mashed potatoes, noodles, or rice. Serve whole pepperoncini on the side or discard.
Notes
Make Ahead: This roast reheats beautifully. Cook 1 day ahead and store the meat in its juices.Storage: Refrigerate leftovers for up to 4 days.Freezing: Freeze shredded roast and gravy separately for up to 3 months. Thaw in the fridge overnight.Reheat: Warm meat with its juices over medium heat on the stovetop.