Slice the flank steak against the grain into thin strips, then season generously with salt and pepper.

Slice the bell peppers and onion into strips.

Layer the seasoned beef at the bottom of your crockpot, followed by the sliced onion and bell peppers.

In a separate bowl, whisk together the low-sodium soy sauce, beef broth, minced garlic, and your cornstarch mixture until smooth. Pour this blend over the ingredients in the crockpot.

Cover and cook on low for 6 hours or high for 3 hours.

Stir gently before serving over rice or noodles to soak up the sauce.