Preheat the oven to 220°C/425°F.
Cut 1 lb (450 g) of potatoes into bite-sized pieces and transfer them to a baking sheet.
Melt 2½ tablespoons of butter and pour it over the potatoes. Season with ½ teaspoon of paprika, garlic powder, black pepper and salt, and ¼ teaspoon of onion powder. Toss well to ensure the potatoes are evenly coated.
Roast for 30–35 minutes, turning once halfway through, until the potatoes are golden and crispy on the outside and tender on the inside. Check they are ready by piercing them with the tip of a knife – it should go in and out easily.
While the potatoes roast, prepare the steak. Cut 1 lb (450 g) of steak into bite-size pieces and pat dry with paper towels. Sprinkle with 1 to 1½ teaspoons of steak seasoning and mix well, either right on the chopping board or in a bowl.
Heat a large frying pan over a medium-high heat. Add 1 tablespoon of butter. When the butter has melted and is hot, add the steak in a single layer. Sear for 2–3 minutes on each side until browned on the outside and still juicy on the inside. Do not move them around too much at first – let them form a good crust. Do not overcrowd the pan – cook in two batches if necessary. If the skillet is overcrowded, the steak will release liquid and steam instead of searing.
Once cooked, push the steak bites to one side of the skillet. Reduce the heat to medium-low. Add 4 tablespoons of butter to the empty side of the pan. Once melted, add 3 minced garlic cloves and cook for 20–30 seconds, just until fragrant. Do not let the garlic brown. It should smell sweet and buttery, not bitter. Stir in the fresh parsley.
Add the roasted potatoes to the skillet. Gently toss the steak and potatoes in the garlic butter until everything is coated.
Turn off the heat. Add a small squeeze of lemon juice and a generous grind of black pepper. If desired, stir in 1 to 2 tablespoons grated Parmesan.
Serve immediately and enjoy!
