Ingredients
1 1/2 pounds beef flank steak, thinly sliced against the grain
3/4 cup fresh orange juice (from about 2–3 oranges)
1/3 cup low-sodium soy sauce
2 tablespoons rice vinegar
2 tablespoons brown sugar (light or dark)
1 tablespoon grated fresh ginger
3 cloves garlic, minced
1 tablespoon toasted sesame seeds
1 tablespoon sesame oil (optional, for richer flavor)
1/4 teaspoon red pepper flakes (optional, for a little heat)
2 tablespoons cornstarch (optional, for thickening sauce at the end)
2 tablespoons cold water (optional, to mix with cornstarch)
2 green onions, thinly sliced (for serving, optional)
Additional toasted sesame seeds, for garnish (optional)
Directions
Thinly slice the flank steak against the grain into bite-size strips and place the raw beef slices evenly in the bottom of your slow cooker.
In a medium bowl or large measuring cup, whisk together the fresh orange juice, soy sauce, rice vinegar, brown sugar, grated fresh ginger, minced garlic, toasted sesame seeds, sesame oil (if using), and red pepper flakes (if using) until well combined. This is your 1 simple mixture.
Pour this 1 mixture evenly over the raw beef slices in the slow cooker, making sure all the meat is coated and mostly submerged in the liquid.
Cover and cook on LOW for 6–7 hours or on HIGH for 3–4 hours, until the beef is very tender and easily pulls apart with a fork.