Preheat oven to 400°F (200°C). In a large bowl, toss the halved or quartered baby Yukon gold potatoes with 2 tablespoons of olive oil, paprika, garlic powder, 1/2 teaspoon kosher salt, and 1/4 teaspoon black pepper until evenly coated. Spread the seasoned potatoes in a single layer on a baking sheet. Roast for 20-25 minutes, or until fork-tender and lightly browned, flipping halfway through.

While potatoes are roasting, pat the steak completely dry with paper towels. This is crucial for a good sear. Season generously on all sides with 1 teaspoon kosher salt and 1/2 teaspoon freshly ground black pepper.

Heat the large cast-iron skillet over high heat for 3-5 minutes until very hot and just smoking. Add 1 tablespoon of olive oil to the hot skillet. Carefully place the seasoned steak in the skillet. Sear for 2-3 minutes per side for medium-rare (internal temperature 130-135°F / 54-57°C), adjusting time for desired doneness.

After searing both sides, reduce heat to medium-low. Add the cold butter pieces, minced garlic, chopped rosemary, and chopped thyme to the skillet. As the butter melts, continuously baste the steak with the fragrant garlic herb butter using a spoon for 1-2 minutes.

Remove the steak from the skillet and transfer it to a cutting board. Let it rest for at least 5-10 minutes to allow the juices to redistribute. Slice the steak against the grain.

Once the potatoes are done, remove them from the oven. Arrange the sliced garlic butter steak and roasted potatoes on plates. Drizzle any remaining garlic butter from the skillet over the steak and potatoes. Garnish with fresh chopped parsley, if desired. Serve immediately.