Creating this incredible Chimichurri Grilled Steak is simple when you follow these steps:

1. Prepare the Chimichurri Sauce: In a bowl, combine the chopped parsley, cilantro, olive oil, red wine vinegar, minced garlic, and red pepper flakes. Add salt and pepper to taste. Mix well and let it sit for at least 10 minutes to allow the flavors to meld.

2. Marinate the Steak: Place the flank steak or sirloin in a resealable plastic bag or shallow dish. Pour half of the chimichurri sauce over the steak, ensuring it’s evenly coated. Seal the bag or cover the dish and marinate in the refrigerator for at least 1 hour, or overnight for more flavor.

3. Preheat the Grill: Heat your grill to medium-high. Make sure it’s well-oiled to prevent sticking.

4. Grill the Steak: Remove the steak from the marinade, allowing excess marinade to drip off. Place the steak on the grill and cook for about 5-7 minutes per side, depending on thickness and desired doneness (135°F for medium-rare, 145°F for medium).

5. Rest: Once cooked, remove the steak from the grill and let it rest for about 5-10 minutes. This allows the juices to redistribute, making the meat more tender.

6. Slice and Serve: Cut the steak against the grain into thin slices. Drizzle the remaining chimichurri sauce over the sliced steak for an extra burst of flavor.

7. Garnish (optional): If you like, squeeze lime juice over the steak just before serving to brighten the flavors.

Following these steps will ensure you serve up a plate of Chimichurri Grilled Steak that is not only delicious but full of flair.