Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.
Toss the cubed Yukon gold potatoes with 0.25 tbsp of olive oil and a portion of the sea salt and black pepper.
Spread the potatoes in a single layer and roast for 20-25 minutes until they are golden and crispy.
Season the sirloin steak evenly on both sides with the remaining sea salt and black pepper.
Heat the remaining 0.25 tbsp of olive oil in a cast-iron skillet over medium-high heat until shimmering.
Place the steak in the skillet and sear for 4-5 minutes per side for medium-rare doneness.
During the last 2 minutes of searing, add the minced garlic, rosemary, and thyme to the pan, spooning the infused oil over the steak.
Add the asparagus spears to the skillet for the final 4 minutes of cooking, turning occasionally until tender and lightly charred.
Remove the steak from the skillet and let it rest for 5 minutes to lock in the juices before slicing.
Plate the sliced steak with the roasted potatoes and charred asparagus, drizzling any remaining pan juices over the top.