Boil a salted pot of water and cook pasta al dente according to package directions.
Meanwhile, take the sausages out of their casings and crumble the meat into a skillet. Sauté over medium-high heat for 5 minutes, stirring occasionally, until it's nicely browned on the outside.
Remove the sausage from the pan and set aside. If there's a lot of fat, discard most of it.
Add the garlic, chicken broth, Dijon mustard, flour, and lemon juice to the pan. Stir until well combined (be sure to scrape up any brown bits from the bottom of the pan) and let it bubble for a minute or two.
Add the sun-dried tomatoes and cream to the pan. Let it cook for 2-3 minutes.
Add the sausage back into the pan. Cook for another few minutes until the sauce has thickened up a bit.
Stir in the basil and spinach. Let it cook for a minute or so until it wilts. Give the sauce a taste and season with extra salt & pepper if needed.
Drain the pasta and toss it with the sauce. Serve immediately with some freshly grated parmesan if desired.