Preheat your oven to 400°F and line a baking sheet with parchment paper.
Toss the cubed sweet potatoes with half of the olive oil, garlic powder, and a pinch of the sea salt and black pepper.
Spread the potatoes in a single layer on the baking sheet and roast for 20-25 minutes until they are golden and crispy on the edges.
Season the tri-tip steak generously on both sides with the remaining sea salt, black pepper, and the finely chopped fresh rosemary.
Heat a cast-iron skillet over medium-high heat with the remaining olive oil.
Sear the steak for 4-5 minutes per side for medium-rare, adding the minced garlic cloves to the pan during the last 2 minutes of cooking to baste the meat.
Transfer the steak to a cutting board and let it rest for 8 minutes to ensure the juices redistribute throughout the meat.
While the steak rests, lightly steam or sauté the asparagus spears in the same skillet until they are tender-crisp and slightly charred.
Slice the tri-tip steak against the grain and serve immediately alongside the roasted sweet potatoes and asparagus.