Ultimate Slow Cooker Pepper Steak Recipe.

1. Cut the flank steak into thin strips and place them in a large ziplock bag.

2. Add the cornstarch to the bag, seal it, and shake well to coat the steak evenly.

3. Heat the olive oil in a large skillet over medium-high heat. Add the coated steak to the skillet and brown it on all sides, stirring occasionally. This should take about 5 minutes.

4. In a separate bowl, mix together the minced garlic, soy sauce, water, and brown sugar until well combined.

5. Transfer the browned steak to a slow cooker and pour the sauce over it. Cover the slow cooker and cook on low heat for 6 hours.

6. After 4 1/2 hours, add the sliced onions, green peppers, and red peppers to the slow cooker. Mix well to combine the ingredients.

7. Cover the slow cooker and continue cooking for an additional 1 1/2 hours, until the vegetables are tender and the steak is fully cooked.