Heat a large skillet over medium heat. Add the ground beef and finely diced onion. Cook for about 6–8 minutes until browned and softened. Stir occasionally. Then add minced garlic and cook for another minute or two until fragrant.
Stir in tomato paste along with salt, black pepper, and red pepper flakes if desired. Cook for an additional minute to enhance flavor.
Pour in the crushed tomatoes and beef broth, stirring to combine. Bring to a simmer.
Add the orzo pasta to the simmering sauce and reduce heat to medium-low. Cover and cook for about 10–12 minutes until the orzo is tender and most of the liquid has been absorbed.
Stir in heavy cream and let it simmer gently for a couple of minutes. Adjust seasoning as needed.
Sprinkle grated Parmesan cheese over the dish and garnish with fresh basil leaves before serving warm.