Combine Fresh Oregano (2 tablespoon), Fresh Parsley (1 bunch), and Fresh Mint (2 tablespoon) herbs in a mixing bowl.
Add in Anchovy Fillets (3), Capers (4 teaspoon), Green Olives (3), Garlic (4 clove) into the bowl of greens.
Add Extra-Virgin Olive Oil (1 cup), Red Wine Vinegar (2 tablespoon), Lemon (1), and Crushed Red Pepper Flakes (1/2 teaspoon) to the bowl.
Stir to combine the marinade.
Place the Flank Steak (2 pound) in a large baking dish. Add half of the marinade and turn to coat. Refrigerate for at least 2 hours.
30 minutes before grilling, remove the steak from the marinade and set out on a plate and cover. Preheat the grill to blazing high heat.
Sprinkle both sides of the steak with Kosher Salt (to taste) and Ground Black Pepper (to taste). Grill over a direct flame until charred on both sides 4-6 minutes per side.
Remove the steak from the grill and allow to rest under tented foil for 5 minutes. Cut the steaks in half and then turn to slice thinly against the grain.
Top with chimi-verde and serve.