Add the parsley, oregano, garlic, red pepper flakes, red wine vinegar, salt, and black pepper to a food processor, leaving out the olive oil. Pulse until the parsley is finely chopped with small, distinct pieces rather than a smooth puree.

Scrape the herb mixture into a small bowl and gently stir in the extra virgin olive oil. Set the sauce aside for 1 hour so the vinegar softens the garlic and the flavors settle together.

Transfer any unused sauce to an airtight container and refrigerate it for up to 3 days. The mixture makes about 3/4 cup, and chilled olive oil may firm up slightly.

Set the steak out 30 minutes before cooking so it loses its refrigerator chill. A less-cold steak cooks more evenly through the center during a fast, high-heat sear.

Heat a BBQ or heavy-based skillet with 1 tbsp vegetable or canola oil over high heat. Wait until the oil is smoking before adding the beef.

Season both sides of the steak generously with salt and pepper immediately before it goes into the heat. The dry surface should make an aggressive sizzle when it meets the hot pan or grill.

Cook the steak over high heat, turning once, until it reaches your preferred doneness. For steak about 2cm / 4/5” thick, use the timing and thermometer cues in the next step.

For medium-rare, cook for 2 min on each side and remove the steak at 52C/125F; for medium, cook for 2 1/2 min on each side and remove it at 57C/135F. After resting, medium-rare rises to 54C/130F and medium rises to 60C/140F.

Move the steak to a plate, cover it loosely with foil, and rest it for 5 - 10 minutes. The center should feel slightly springy when pressed, and the juices should stay mostly within the meat rather than flooding the plate.

Slice the rested steak thinly against the grain and serve the chimichurri on the side. Each slice should show a browned exterior and a warm pink center when cooked medium-rare.