01 -
Combine flank steak with half of the parsley, half of the minced garlic, half of the olive oil, half of the red wine vinegar, salt, and pepper in a shallow dish. Coat evenly and marinate under refrigeration for at least 60 minutes.
02 -
Preheat grill to medium-high. Place marinated steak on the grill and cook approximately 6 minutes per side, or until preferred doneness. Transfer to a cutting board and let rest for 5 minutes, then slice thinly against the grain.
03 -
In a blender, combine avocado, remaining parsley, remaining garlic, remaining olive oil, and remaining red wine vinegar. Blend until smooth; season with salt and pepper to taste.
04 -
Place a flour tortilla on a flat surface. Sprinkle with half the cheese, distribute sliced grilled steak evenly, and drizzle with avocado chimichurri. Top with remaining cheese and a second tortilla.
05 -
Heat a large skillet over medium heat. Carefully transfer assembled quesadilla to the skillet. Cook each side for approximately 3 minutes or until golden brown and cheese is melted.
06 -
Slice quesadilla into wedges. Serve immediately, garnished with additional avocado chimichurri if desired.