Heat olive oil in a large skillet over medium-high heat.
Add ground beef and cook, breaking it up with a spoon, until browned and cooked through, about 5-7 minutes.
Add chopped onion to the skillet and cook until softened, about 3 minutes.
Stir in minced garlic and cook for 1 minute until fragrant.
Add orzo pasta to the skillet and stir to combine with the beef mixture.
Pour in diced tomatoes with their juice and beef broth.
Add dried oregano, dried basil, salt, black pepper, and crushed red pepper flakes. Stir well.
Bring the mixture to a boil, then reduce heat to low and cover the skillet.
Simmer for 12-15 minutes, or until the orzo is tender and most of the liquid is absorbed, stirring occasionally.
Remove from heat and stir in grated Parmesan cheese and chopped fresh parsley.
Serve hot, garnished with additional Parmesan cheese if desired.