In a large zip top bag, combine the lemon juice, oil, soy sauce, Worcestershire sauce, salt, pepper, garlic powder, and parsley flakes.
Seal the bag and then shake to mix.
Add the steaks to the bag and zip to the top shut, removing as much air as possible.
Marinate the steaks for as little as 2 hours and up to overnight.
Prepare your steaks, as desired.
To grill, preheat your grill to high heat.
Sear on each side for 3 minutes.
Reduce the heat to approx 350° and continue to cook until internal temp reaches desired doneness. 140° is medium rare, 155° is medium, and 165° is well done.
Allow the steaks to rest for 5-10 minutes before serving.