Ingredients:

Instructions:

  1. Cube the beef into roughly uniform 1-inch pieces and place them directly into the slow cooker insert.
  2. In a separate bowl, whisk together the soy sauce, beef broth, Worcestershire sauce, brown sugar, garlic powder, onion powder, and black pepper.
  3. Pour the marinade mixture evenly over the steak cubes in the slow cooker. Stir gently to ensure all pieces are coated. Cover and cook on LOW for 4-6 hours or HIGH for 2-3 hours, until the steak is fork-tender.
  4. About 30 minutes before serving, combine the cornstarch and cold water in a small bowl to create a smooth slurry.
  5. Remove the lid from the slow cooker. Stir the cornstarch slurry into the hot liquid in the cooker. Replace the lid and cook on HIGH for 15-20 minutes until the sauce has thickened noticeably.
  6. Turn the slow cooker off. Stir in the cold cubes of unsalted butter, one cube at a time, until fully melted and incorporated, creating a glossy, rich sauce. Do not cook after adding the butter.
  7. Garnish generously with fresh chopped parsley and serve immediately over mashed potatoes or rice.