In a large skillet, heat the olive oil over medium-high heat. Add the sliced flank steak and season with garlic powder, onion powder, salt, and pepper. Cook for about 3-4 minutes until browned. Remove the steak from the skillet and set aside.
In the same skillet, add the rice and toast it for about 2 minutes, stirring frequently.
Pour in the beef broth and bring to a boil. Reduce the heat to low, cover, and let it simmer for 15 minutes.
After 15 minutes, stir in the frozen mixed vegetables and the cooked steak. Cover and cook for an additional 5 minutes until the vegetables are heated through and the rice is tender.
Remove from heat and sprinkle the shredded cheddar cheese on top. Cover for a few minutes until the cheese is melted.
Garnish with sliced green onions before serving.