To a large skillet over medium-high heat, add the ground beef and diced onion. Cook for 5–6 minutes, breaking the meat apart as it browns. Once no longer pink, drain excess grease, if needed.
Add onion powder, garlic powder, paprika, salt, and pepper. Stir to evenly coat. Add the minced garlic and red pepper flakes and cook for 1 more minute.
Pour in the Worcestershire sauce, beef broth, and rice. Bring to a boil, then reduce heat to medium-low. Cover and simmer for 10 minutes.
After 10 minutes, stir in the chopped broccoli. Cover and continue to simmer for another 5–7 minutes, or until rice is tender and most of the liquid has absorbed.
In a small bowl, combine the white cheddar and mild cheddar cheese.
Stir in half of the cheese mixture until melted and fully incorporated.
Sprinkle the remaining cheese on top. Remove from heat, cover, and let rest for 2–3 minutes until the cheese melts.
Serve warm.