Preheat oven to 450 degrees.

Remove the steaks from the fridge and season with 1 teaspoon salt and a light shower of freshly ground black pepper.

Cut the potatoes in quarters (or in half if they are quite small). Put into a medium pot and cover by 11/2 inches with water. Add enough salt so the water tastes like the sea. Bring to a boil and boil until the potatoes are very tender (you can slip a paring knife into the center with ease). Drain well.

While the potatoes cook, make the chimichurri by putting the cilantro, parsley, garlic, red pepper flakes, vinegar, ⅓ cup olive oil, and ¼ teaspoon salt into a blender or food processor and run until finely chopped but not pureed. Set aside.

Transfer the boiled potatoes to a parchment-lined baking sheet, toss with 1 tablespoon olive oil, and season with salt and pepper to taste. Spread out on the baking sheet and roast until golden brown, about 25 minutes (you can always blast them under a broiler if you want to speed things up).

While the potatoes brown, set a large cast iron skillet (or other heavy pan) over medium-high heat and leave it for several minutes until you can feel the heat under your palm when you hover it just above the surface of the pan. Add the canola oil and swirl to coat the bottom. Lay down the steaks and cook until deeply browned, 4 to 5 minutes. Turn the steaks over and continue to cook until done to your liking, an additional 3 to 4 minutes for medium-rare (125 degrees on an instant read thermometer; temperature will rise as it rests). Cook an additional 1 to 2 minutes  for medium or medium-well. Transfer to a serving platter to rest for at a good 10 minutes.