In a mixing bowl, combine olive oil, lime zest, lime juice, minced garlic, cilantro, salt, and pepper. Add the flank steak and marinate for at least 30 minutes.
Grill or pan-sear the marinated steak over medium-high heat for about 6-8 minutes per side for medium doneness. Let it rest before slicing.
In serving bowls, layer cooked rice, black beans, corn, sliced steak, and avocado. Top with cilantro lime crema and optional add-ins if desired.
Notes
You can customize your bowls with your favorite toppings like chopped lettuce or sautéed vegetables.