Preheat the oven to 220°C. Line a large rimmed baking sheet with parchment paper or foil.
Toss the potatoes with 1 tablespoon olive oil, paprika, Italian seasoning, ½ teaspoon salt, and half the pepper.
Spread the potatoes cut-side down on the pan. Roast for 20–25 minutes, turning once, until nearly tender and golden.
Mix the softened butter, garlic, parsley, lemon juice, remaining salt, and remaining pepper in a small bowl.
Pat the steaks dry and rub both sides with the remaining olive oil. Spread a little garlic butter over each steak.
Move the potatoes toward the edges of the pan and place the steaks in the center.
Roast for 6–10 minutes, turning the steaks halfway through, until cooked to your liking. For medium-rare, aim for about 54–57°C before resting.
Transfer the steaks to a board and rest for 5–8 minutes. Toss the hot potatoes with half the remaining garlic butter.
Slice the steaks and return them to the pan. Spoon over the remaining garlic butter and sprinkle with extra parsley. Serve with a green salad or roasted vegetables. Refrigerate leftovers for up to 3 days.
