Marinate the flank steak in a mixture of olive oil, garlic powder, chili powder, cumin, lime juice, salt, and pepper for at least 30 minutes.
Heat a large skillet or grill over medium-high heat.
Once hot, add the marinated flank steak to the skillet. Cook for 4-5 minutes on each side for medium-rare.
Remove the steak from the skillet and let it rest for 5-10 minutes before slicing.
In the same skillet, add the sliced onions and bell peppers, cooking for 3-4 minutes until they soften.
As the vegetables cook, season them with additional salt, pepper, and more lime juice.
Once the veggies are finished, assemble your bowl by layering sliced steak and sautéed vegetables.
Garnish with chopped cilantro and serve hot, drizzled with any remaining lime over the top.