Start by generously seasoning the flank steak with chili powder, cumin, salt, and black pepper. Let it sit for about 10 minutes.

In a large skillet, heat olive oil over medium-high heat. Sear the seasoned steak for 4-5 minutes on each side.

Reduce the heat, add more olive oil if needed, and sauté diced onions until translucent. Add minced garlic for an additional 30 seconds.

Stir in the cooked white rice and diced tomatoes, mix thoroughly, and heat for 2-3 minutes.

Pour cheese sauce over the rice and steak mixture, stir to combine, and warm through for 2-3 minutes.

Remove from heat, slice the steak, fold it into the mixture, and garnish with cilantro before serving.