Preheat oven: Set your oven to 300°F (150°C).
Combine sauce: In a large mixing bowl, whisk together the cream of mushroom soup, onion soup mix, beef broth, Worcestershire sauce, soy sauce (if using), garlic powder, and pepper.
Assemble: Place beef tips in a baking dish or Dutch oven. Pour the sauce mixture evenly over the top and stir to coat well.
Seal tightly: Cover with foil or a lid — this is where the “no peek” magic happens. Don’t lift the lid until it’s done baking.
Bake: Place in the oven and bake for 2½ to 3 hours, until beef is fork-tender and the gravy is rich and thick.
Serve: Stir gently, garnish with parsley, and serve hot over mashed potatoes, rice, or egg noodles.