In a small bowl, combine softened butter and truffle paste until smooth; roll into a log using plastic wrap and refrigerate until firm.
To make the chimichurri, whisk together parsley, garlic, red wine vinegar, extra virgin olive oil, oregano, and red pepper flakes in a medium bowl; set aside at room temperature.
Heat frying oil in a heavy pot to 375°F (190°C). Fry potato strips in batches for 5-7 minutes until golden brown and crispy; drain on paper towels.
Pat steaks dry with paper towels and season both sides heavily with salt and black pepper.
Heat vegetable oil in a cast-iron skillet over high heat until smoking. Sear steaks for 4 minutes per side for medium-rare (internal temperature 130°F/54°C).
Remove steaks from skillet and let rest on a cutting board for 5 to 8 minutes.
Toss the hot fries in a large bowl with half of the prepared chimichurri sauce and a pinch of salt.
Slice the truffle butter into rounds. Plate the steaks with a round of butter on top and serve alongside the chimichurri fries with remaining sauce for dipping.