01 -
Cut the beef chuck roast into 3-4 large pieces and pat dry. Lightly sprinkle onion soup mix over all sides of the beef pieces. Heat vegetable oil in a cast iron skillet over medium-high heat. Sear each side of the beef pieces for 2-3 minutes without disturbing, until a caramelized crust forms.
02 -
Spray the inside of the slow cooker with non-stick spray. Place seared beef pieces in a single layer inside the slow cooker.
03 -
Evenly sprinkle the remaining onion soup mix and powdered brown gravy mix over the beef. Pour red wine vinegar over the contents if using.
04 -
Cover and cook on low heat for 8 hours or until the beef is tender and easily shredded with a fork. Avoid lifting the lid during cooking to maintain temperature and moisture.
05 -
While the beef cooks, prepare mashed potatoes and garlic Texas toast according to their package directions or your preferred method.
06 -
Place one slice of garlic Texas toast on each plate. Top with ½ cup mashed potatoes, then add ½ to 1 cup of shredded beef. Drizzle with cooking gravy from the slow cooker and garnish with fresh minced parsley if desired. Serve alongside steamed or roasted vegetables.