In a medium bowl, whisk together 1 tablespoon olive oil, lime juice, cumin, chili powder, garlic powder, salt, and pepper.
Toss the sliced steak in the marinade and refrigerate for 30 minutes.
In a separate bowl, combine the cooked rice with lime zest and fresh cilantro.
Heat the remaining 1 tablespoon olive oil in a cast-iron skillet over medium-high heat.
Add bell peppers and onions to the skillet and sauté for 6 minutes until tender and charred; remove and set aside.
Increase heat to high, add the marinated steak in a single layer, and sear for 3 minutes per side until browned.
Divide the cilantro rice into four bowls.
Top each bowl with steak, sautéed vegetables, black beans, corn, and avocado slices before serving.