Add beef, sausage, onions, and garlic to a large stockpot over medium heat and brown the meat.
Add the tomato sauce, diced tomatoes, Italian herbs, salt, black pepper, cayenne pepper, and fresh basil to the sauce. Let simmer for at least 15 minutes, up to an hour. The longer, the better! If you’re using spinach, add for the last ten minutes of cooking to soften and wilt.
Cook the fusilli according to package directions for al dente pasta.
Top cooked pasta with meaty sauce, feta, and fresh basil for serving.