Blend cilantro, lime juice, garlic, olive oil, cumin, salt, and pepper until smooth.
Place the steak in a zip-top bag or shallow dish and pour the marinade over it. Refrigerate for at least 30 minutes or up to 4 hours.
Rinse the rice thoroughly.
Combine rice, water or broth, and salt in a saucepan. Bring to a boil, reduce heat, cover, and simmer until tender.
Remove rice from heat, let rest for 5 minutes, then fluff with a fork. Stir in chopped cilantro and lime juice.
Remove the steak from the marinade and pat dry.
Heat a cast-iron skillet over high heat with a drizzle of oil.
Cook the steak for 3–5 minutes per side, depending on thickness, until it reaches your preferred doneness.
Let the steak rest for 10 minutes before slicing thinly against the grain.
Assemble the Cilantro Lime Steak Bowls by adding rice to serving bowls. Top with sliced steak, black beans, corn, avocado, lettuce, salsa, and fresh lime wedges.