01 - Lightly spray the inside of your slow cooker with nonstick cooking spray to prevent sticking.
02 - Place the sliced flank steak in the prepared slow cooker, arranging the pieces evenly.
03 - In a medium bowl, whisk together soy sauce, brown sugar, hoisin sauce, and minced garlic until the sugar is mostly dissolved and the mixture is well combined.
04 - Pour the sauce mixture over the beef and toss thoroughly to ensure all pieces are evenly coated.
05 - Cover and cook on LOW setting for 4 hours, or until the beef is tender and the sauce has slightly thickened.
06 - Stir well before serving. Serve hot over steamed rice or with steamed vegetables for a complete meal.