Place halved potatoes in cold, salted water and bring to a boil. Cook for 6–8 minutes until just fork-tender but not falling apart. Drain and set aside.

Pat steak cubes dry with paper towels. Season generously with salt, pepper, and smoked paprika.

Heat 1 tbsp oil in a large cast-iron skillet over medium-high heat until shimmering. Add steak in a single layer; sear for 1–2 minutes per side until golden brown.

In the same skillet, add parboiled potatoes cut-side down. Let them brown undisturbed for 3–4 minutes, then toss and repeat.

Push potatoes to one side and add butter plus minced garlic to the pan. Stir briefly until fragrant, then mix with potatoes. Return seared steak to the skillet and toss to coat.

Finish with lemon juice and chopped parsley. Taste and adjust salt and pepper. Serve immediately.