In a large soup pot or Dutch oven, heat over medium-high heat, and add the lean ground beef. Allow it to cook undisturbed for about 5–6 minutes until browned and caramelized on the bottom. Use a spatula to start breaking the meat into smaller pieces.

Add the half medium onion to the pot, stirring to combine with the beef. Cook for an additional 5 minutes until the onion becomes translucent and tender. If you're using fatty beef, drain any excess fat.

Stir in the minced garlic, crushed red pepper flakes (if using), and Italian seasoning, cooking for about 1 minute until aromatic. Then, add in the uncooked orzo pasta, giving it a quick stir.

Pour in the tomato sauce, beef broth, heavy whipping cream, and Worcestershire sauce. Stir well and bring to a gentle bubble over medium heat. Allow it to cook uncovered for about 10 minutes.

Once the orzo is tender and the sauce has thickened slightly, remove the pot from heat. Stir in the Parmesan cheese and spinach until the spinach wilts. Cover for 3–5 minutes to allow the cheese to melt.

Taste and adjust with salt and pepper according to your preference. Serve hot.