Preheat your oven to 400°F.
Wash the baby potatoes and cut larger ones in half, if needed. Toss them with olive oil, salt, and pepper, and spread them evenly on a baking sheet.
Roast the potatoes in the oven for 20-25 minutes until they are golden and tender, stirring halfway through.
While the potatoes roast, season the steak generously with salt and pepper on both sides.
Heat a skillet over medium-high heat. Once hot, add the steak and cook for about 3-4 minutes per side for medium-rare (adjust time to your preferred doneness).
In the last minute of cooking, add the butter, crushed garlic, and rosemary to the pan. Spoon the melted herb-garlic butter over the steak for added flavor.
Remove the steak from the skillet and let it rest for a few minutes. Slice the steak against the grain and garnish with fresh parsley.
Serve the sliced steak alongside the roasted baby potatoes. Enjoy your balanced, flavorful meal!