Preheat your Oven to 425°F. Line a large Baking Sheet with Aluminum Foil or Parchment Paper for easy cleanup. In a large Mixing Bowl, toss the 1 ½ lb Yukon Gold potatoes cut into 1-inch cubes cubes with 2 tablespoons of 3 tbsp olive oil divided, half the 4 cloves garlic minced, ½ tsp 1 tsp smoked paprika, ½ tsp 1 tsp kosher salt plus more, and a few grinds of ½ tsp black pepper freshly ground until evenly coated. Spread them in a single layer on one side of the prepared Baking Sheet, making sure they aren't crowded.

Roast the 1 ½ lb Yukon Gold potatoes cut into 1-inch cubes for 15 minutes, flipping once halfway through, until they begin to turn golden on the edges.

While the 1 ½ lb Yukon Gold potatoes cut into 1-inch cubes roast, pat the 1 ½ lb sirloin steak cut into 1½-inch cubes cubes dry with paper towels. In a Mixing Bowl, Whisk together the melted 2 tbsp unsalted butter melted, remaining 1 tablespoon 3 tbsp olive oil divided, remaining 4 cloves garlic minced, remaining ½ tsp 1 tsp smoked paprika, 1 tsp Worcestershire sauce, 1 tbsp fresh rosemary finely chopped, 1 tsp fresh thyme leaves finely chopped, remaining ½ tsp 1 tsp kosher salt plus more, and ½ tsp black pepper freshly ground. Add the 1 ½ lb sirloin steak cut into 1½-inch cubes cubes and toss to coat thoroughly.

After the 1 ½ lb Yukon Gold potatoes cut into 1-inch cubes have had their 15-minute head start, push them to one side and arrange the seasoned 1 ½ lb sirloin steak cut into 1½-inch cubes cubes in a single layer on the other side of the Baking Sheet. Return the pan to the Oven and roast for 12–15 minutes, until the 1 ½ lb sirloin steak cut into 1½-inch cubes reaches your desired doneness (130–135°F for medium-rare, 145°F for medium) and the 1 ½ lb Yukon Gold potatoes cut into 1-inch cubes are fork-tender and golden.

Remove the pan from the Oven and let the 1 ½ lb sirloin steak cut into 1½-inch cubes rest for 5 minutes — this keeps it juicy. Taste the 1 ½ lb Yukon Gold potatoes cut into 1-inch cubes and adjust seasoning if needed. Scatter fresh 2 tbsp fresh flat-leaf parsley roughly chopped over everything and serve directly from the pan.