I heated the pot to medium-high, added the lean ground beef, and let it brown undisturbed for a few minutes. Once the bottom formed some color, I stirred in the chopped onion, breaking the meat into small pieces. After a few minutes I added the garlic, crushed red pepper flakes, and Italian seasoning, letting them cook until fragrant.
I stirred in the uncooked orzo, letting it toast a bit among the aromatics. Then I poured in the tomato sauce, beef broth, heavy cream, and Worcestershire sauce. The pot was brought up to a gentle simmer, stirring occasionally so the orzo wouldn’t stick, and I kept an eye on the liquid levels to prevent drying out or burning.
When the orzo was fully cooked (about 10 more minutes or so), I removed the pot from heat, stirred in freshly grated Parmesan and fresh baby spinach. I covered the pot for 3-5 minutes so the spinach could wilt and the sauce would thicken. Finally, I tasted it and adjusted salt and pepper before serving.