
In a glass bowl, place pineapple juice, lime zest, lime juice, 2 minced or grated garlic cloves, and chopped parsley into a bowl and mix well. Set aside.
Place flank steak on a piece of parchment paper. Add 1 teaspoon salt, 1/2 teaspoon of pepper, garlic and onion powder to the top of the steak. Repeat this on the other side.
Place flank steak in a zip lock bag and pour the marinade down on top. Marinate for 30-32 hours.
Heat your grill to 500 degrees. Place the steak on the grill and sear BOTH sides for 2 minutes. Then move the steaks to indirect heat and cook 9-12 minutes, turning half way through. Each side should cook the same amount of time. The internal temperature should read 140 degrees.
Remove from the grill. Let the flank steak rest for about 10 minutes before slicing. This allows the juices to stay inside the meat. Enjoy!