Prepare the fries: Peel and cut the potatoes into 1/4-inch thick sticks. Soak in cold water for 30 minutes to remove excess starch, then pat dry thoroughly.

First fry: Heat vegetable oil in a deep fryer or large pot to 325°F (160°C). Fry the potatoes in batches for 4-5 minutes until soft but not browned. Drain on paper towels.

Season the steaks: Pat the steaks dry with paper towels. Generously season both sides with salt and pepper. Let sit at room temperature for 15 minutes.

Cook the steaks: Heat a cast-iron skillet over high heat. Add 1 tbsp oil. Sear steaks for 3-4 minutes per side for medium-rare. Add butter, thyme, and garlic during the last 2 minutes, basting the steaks with the melted butter.

Second fry: Increase oil temperature to 375°F (190°C). Fry the potatoes again in batches for 2-3 minutes until golden and crispy. Drain and season immediately with salt.

Rest and serve: Transfer steaks to a cutting board, tent with foil, and rest for 5 minutes. Slice against the grain and serve with the crispy fries.