In a bowl, whisk together the lime juice, olive oil, minced garlic, chopped cilantro, cumin, chili powder, salt, and pepper to create a marinade.
Place the flank steak in a large resealable bag or shallow dish and pour the marinade over it. Seal or cover and let it marinate in the refrigerator for at least 30 minutes (up to 4 hours for more flavor).
Preheat a grill or grill pan over medium-high heat. Remove the steak from the marinade and discard the marinade.
Grill the steak for about 4-5 minutes on each side or until it reaches your preferred doneness. Let it rest for 5 minutes before slicing against the grain into thin strips.
To assemble the bowls, start with a base of cooked quinoa. Top with sliced steak, black beans, corn, avocado, and cherry tomatoes.
Garnish with lime wedges and any optional toppings like feta cheese, radish slices, or extra cilantro.
Notes
Marinate the steak for longer for enhanced flavor.