In a resealable bag, combine lime juice, soy sauce, scallions, ginger, and red pepper flakes.
Add steak and seal bag.
Marinate in fridge, turning occasionally, for up to an hour (I usually go longer).
Heat grill to high. Place steak on grates, season with salt and pepper. Cover.
Cook, turning once, until meat reaches desired doneness. 6-8 minutes for medium-rare.
Let rest 10 minutes before thinly slicing.
This recipe does not contain many non-starchy vegetables. To maximize your results, it is highly recommended that you eat at least three servings of non-starchy vegetables via a SANE side dish or green smoothie along with this main dish.