Bring a large pot of salted water to a boil. Add the beef tortellini and cook according to package instructions until al dente, about 3-5 minutes. Drain and set aside.
While the tortellini cooks, heat olive oil in a large skillet over medium-high heat.
Add the ground beef to the skillet and cook, breaking it up with a spoon, until browned and cooked through, about 6-8 minutes. Drain excess fat if necessary.
Add the chopped onion to the beef and cook until softened, about 3-4 minutes.
Stir in the minced garlic and cook for 1 minute until fragrant.
Add the diced tomatoes with their juices, beef broth, tomato paste, dried oregano, dried basil, and crushed red pepper flakes. Stir to combine.
Bring the sauce to a simmer and cook for 8-10 minutes, stirring occasionally, until slightly thickened.
Season the sauce with salt and freshly ground black pepper to taste.
Add the cooked tortellini to the skillet and gently toss to coat with the sauce.
Remove from heat and sprinkle with grated Parmesan cheese and chopped fresh parsley before serving.