Steps
1. Preheat oven to 200°C (392°F).
2. Toss diced potatoes with half the olive oil, rosemary, salt, and pepper. Spread on a baking sheet and roast for 25 minutes, turning halfway.
3. While potatoes roast, season beef steak with salt and pepper.
4. Heat a skillet over medium-high heat and add remaining olive oil.
5. Sear steak for 3-4 minutes on each side for medium-rare (adjust time for preferred doneness).
6. In the last minute of cooking, add butter and garlic to the pan, spooning melted garlic butter over steak.
7. Remove steak and let rest for 5 minutes.
8. Plate steak with roasted potatoes and garnish with fresh parsley.