Preheat the oven to 425˚F.
Cut the potatoes into evenly-sized sticks or wedges and toss with a drizzle of oil to coat.
Spread out on a parchment-lined baking sheet and bake for 20 minutes, turning once or twice, until golden and crisp.
Meanwhile, season the steaks with salt. Set a heavy (cast iron is ideal) skillet over medium-high heat.
Add some oil to the skillet and when it’s hot, cook the steaks for about 4 minutes, or until a deep crust has developed on the bottom.
Flip and cook for another 4-5 minutes (for medium-rare) or until done to your liking.
Transfer to a cutting board to rest for 5 minutes while you add the butter to the hot pan; let it melt, stirring to loosen any browned bits on the bottom of the pan.
Drizzle over the steak and serve with fries.