In a bowl, whisk together honey, soy sauce, minced garlic, olive oil, apple cider vinegar, black pepper, and red pepper flakes.
Place the skirt steak in a resealable plastic bag and pour the marinade over it. Seal the bag and refrigerate for at least 1 hour, preferably overnight.
Preheat the grill to medium-high heat. Remove the steak from the marinade and let excess drip off.
Grill the steak for 4-5 minutes per side for medium-rare, or longer to desired doneness.
Let the steak rest for 5 minutes before slicing against the grain. Serve with remaining marinade if desired.
Notes
This dish pairs wonderfully with grilled vegetables or a fresh green salad.