Place the cubed baby gold potatoes into a medium saucepan, cover with cold water by 1 inch, and add 1 teaspoon salt. Bring to a boil over high heat and simmer for 5 to 6 minutes until just fork-tender. Drain thoroughly and let steam dry on a clean kitchen towel for 3 minutes.

Pat the sirloin steak cubes thoroughly dry with paper towels. Season evenly on all sides with ½ teaspoon kosher salt, black pepper, smoked paprika, and garlic powder. Ensuring dry meat guarantees a deep, caramelized crust.

Heat 1 tablespoon olive oil in a large 12-inch heavy cast-iron skillet over medium-high heat until shimmering. Add the par-boiled potatoes in a single layer and cook undisturbed for 3 to 4 minutes, then toss and sear for another 3 minutes until deeply golden and crispy on all sides. Transfer potatoes to a plate.

Add the remaining 1 tablespoon olive oil to the hot skillet over high heat. Add the seasoned steak bites in a single layer without crowding (cook in two batches if necessary). Sear undisturbed for 2 minutes, then flip and sear for 1.5 to 2 minutes more until a dark golden-brown crust forms while keeping the centers tender and medium-rare (internal temp 130°F–135°F / 55°C–57°C). Transfer steak bites to the plate with potatoes.

Reduce skillet heat to medium-low. Add the butter, minced garlic, rosemary sprigs, and thyme. Swirl continuously for 60 seconds until the butter foams, turns lightly golden, and becomes intensely fragrant. Pour in the beef bone broth to deglaze, scraping up every bit of flavorful browned fond from the skillet bottom.

Return the crispy potatoes and seared steak bites along with their resting juices back into the bubbling garlic herb butter. Toss vigorously for 60 seconds to coat every piece in the glossy butter glaze. Remove from heat, scatter chopped fresh parsley and flaky sea salt over the top, and serve immediately straight from the skillet.