Marinade: Add oil, soy sauce, peach juice, minced onion and parsley to a large ziplock bag. Add the flank steak to the bag, seal it, and lay it flat in your fridge to marinate for 3-6 hours.

Grill: Remove steak from the fridge about 20 minutes before grilling. Heat grill to high heat.

Clean and oil grill grates and add steak, discarding the marinade. Cook for 3-4 minutes, then flip to the other side and cook for 3-4 more minutes, or until desired doneness: 125 to 130°F for rare, 140°F for medium rare, and 150°F for medium.

Rest: Remove steak, cover with foil and rest for 5-10 minutes before slicing into very thin pieces, against the grain.