In a small bowl, whisk together the extra virgin olive oil, lime juice, ground cumin, garlic powder, sea salt, and black pepper to create the marinade.
Place the flank steak in a shallow glass dish or resealable bag and pour the marinade over it, ensuring it is well coated; let it marinate for at least 15 minutes at room temperature.
Preheat a grill or heavy-bottomed grill pan over medium-high heat until very hot.
Trim the woody ends off the asparagus spears and toss them with the avocado oil and a tiny pinch of salt.
Place the steak on the grill and cook for 4-5 minutes per side for medium-rare, or until it reaches your desired level of doneness.
Remove the steak from the grill and transfer to a cutting board; let it rest for 5-8 minutes to keep the juices inside.
While the steak rests, place the asparagus on the grill and cook for 3-5 minutes, turning occasionally until tender and marked with char lines.
Slice the steak thinly against the grain and serve alongside the grilled asparagus, garnished with fresh chopped cilantro.