Creating Slow Cooker Mongolian Beef is straightforward. Follow these simple steps:

1. Prepare the Beef: Slice the flank steak thinly against the grain for maximum tenderness.
2. Mix the Sauce: In a bowl, whisk together the soy sauce, brown sugar, cornstarch, garlic, ginger, and sesame oil until well combined.
3. Combine Ingredients: Place the sliced beef into the slow cooker. Pour the sauce mixture over the beef, ensuring all pieces are coated.
4. Add Broth: Pour in the beef broth to add moisture and enhance the flavors.
5. Set the Slow Cooker: Cover and cook on low for 4-6 hours or high for 2-3 hours. The beef should be tender and the sauce thickened.
6. Garnish: Once cooked, stir the beef and sauce, then garnish with sliced green onions.
7. Prepare to Serve: Serve hot over cooked rice or noodles for a complete meal.

These steps will guide you in creating this incredible dish effortlessly. The result is a hearty meal that will have everyone asking for seconds!