Preheat your oven to 425°F and line a baking sheet with parchment paper.
Slice the russet potato into thin, uniform wedges and place them in a bowl.
Toss the potato wedges with 1 teaspoon of olive oil and half of the sea salt and black pepper.
Spread the wedges in a single layer on the baking sheet and roast for 20-25 minutes, flipping halfway through, until golden and crisp.
While the fries are roasting, mince the garlic and finely chop the fresh parsley.
Pat the sirloin steak dry with a paper towel and season both sides with the remaining salt and pepper.
Heat the remaining 0.5 teaspoon of olive oil in a cast-iron skillet over medium-high heat until it begins to shimmer.
Place the steak in the hot skillet and sear for 3-4 minutes per side for medium-rare, or until it reaches your desired doneness.
Remove the steak from the pan and let it rest on a cutting board for 5 minutes to keep it juicy.
Remove the fries from the oven and immediately toss them with the minced garlic, grated parmesan, and fresh parsley.
Slice the steak against the grain and serve immediately alongside the hot garlic parmesan fries.