Preheat your oven to 425°F and line a baking sheet with parchment paper.
Slice the russet potato into thick wedges, toss with the olive oil and a pinch of sea salt, then bake for 25 minutes until golden.
Season the sirloin steak with a blend of cumin, chili powder, and salt before placing it on a preheated grill over medium-high heat.
Grill the steak for approximately 4-5 minutes per side or until it reaches your desired level of doneness.
Transfer the steak to a cutting board and let it rest for five minutes to ensure the meat stays juicy.
While the steak rests, finely dice the tomato, onion, and cilantro, then mix them together with lime juice to create the fresh salsa.
Warm the corn tortillas briefly on the grill or in a dry pan until pliable.
Thinly slice the steak against the grain and divide it between the tortillas, topping each with a generous spoonful of salsa and serving with the potato wedges.