While cooking sauce cook your pasta al dente and drain. Dice and caramelize onion in butter. Add Italian sausage to onions and brown. If in casings remove from casings. When sausage is browned add garlic and cook for another minute or two. Drain excess fat if you want to. I leave it in and dish does not come out greasy.
Add chicken broth to sausage mixture and simmer for about 5 minutes. Now add crushed tomatoes, paste, salt, pepper, and a heaping tablespoon of cajun seasoning (if wanting it milder just add a teaspoon or two and use mild sausage). Let simmer for a few more minutes. Add heavy cream and simmer for a couple of minutes.
Now add pasta and parmesan cheese to sauce and let simmer for 5 minutes. We prefer this recipe with mostaccioli pasta, but I have made it with several different types of pasta and it has been good with all of them. So just use your favorite.
This recipe started from TRACY JOYNER's recipe on here. As I stated in the description I have combined a couple of recipes with Tracy's to come up with this. I wanted to make sure Tracy got credit for being the inspiration of this dish.