In a small bowl, mix together the lime juice, lime zest, chopped cilantro, minced garlic, cumin, paprika, salt, and black pepper to create a marinade.
Place the flank steak in a shallow dish or a resealable plastic bag. Pour the marinade over the steak, ensuring it's well coated. Let it marinate for at least 30 minutes (or up to 2 hours in the refrigerator for more flavor).
Preheat a grill or grill pan over medium-high heat. Remove the steak from the marinade and discard the leftover marinade.
Grill the steak for about 5-7 minutes per side, or until it reaches your desired level of doneness (medium rare is recommended for flank steak).
Once cooked, remove the steak from the grill and let it rest for 5 minutes before slicing it against the grain into thin strips.
To assemble the bowls, start with a base of quinoa or rice in each bowl.
Add sliced steak on top of the grain base, then layer with cherry tomatoes, avocado, corn, black beans, and red onion.
Garnish with additional chopped cilantro, sliced jalapeños for heat, and lime wedges for drizzle.
Notes
For extra flavor, marinate the steak for up to 2 hours.