In a small bowl, whisk together olive oil, minced garlic, lime juice, lime zest, chopped cilantro, ground cumin, chili powder, salt, and pepper until fully combined.

Place flank steak in a dish or resealable bag, pour marinade over it, seal tightly, and refrigerate for at least 1 hour.

Preheat your grill to medium-high and lightly oil the grates to prevent sticking.

Remove the steak from the marinade, letting excess drip off. Grill for 4-5 minutes on each side until desired doneness.

Allow the steak to rest for 5 minutes before slicing thinly against the grain.

While the steak is grilling, prepare rice in a saucepan with beef broth according to package instructions.

In a large bowl, mix the cooked rice, drained black beans, and corn kernels until well combined.

Divide the rice and bean mixture among serving bowls. Top each with slices of grilled steak, creamy avocado, red onion, and jalapeño if desired.

Just before serving, squeeze fresh lime wedges over the bowls.