Cook pasta noodles according to package instructions.
Meanwhile, brown ground beef with chopped onion. Drain, rinse. Return to skillet. Add pasta sauce. Let simmer for 10 minutes.
While ground beef is browning, cook the spinach in the microwave as directed. Once cooked, drain off as much liquid as you can. Then stir into the meat sauce.
Serve Spinach Spaghetti to the hungry masses.