Preheat the grill to medium-high heat. Season steak with ¾ teaspoon salt and black pepper to taste.
While the grill is heating, place the shallot, garlic, and red wine vinegar in a small bowl. Let sit for 10 minutes. Then, stir in the parsley, oregano, olive oil, and remaining ¾ teaspoon of salt. Set the chimichurri aside.
Place the steak on the hot grill. Cook for 2 minutes, then flip and continue cooking for 1 to 2 minutes, or until the desired doneness is reached.
Remove from the grill and let sit for 10 minutes. Slice thinly against the grain, transfer to a serving platter, and top with the chimichurri. Serve immediately.