Heat oil in a large, nonstick pan over medium-high heat. Add sausages then brown on both sides – they do not need to be cooked all the way through. Remove to a plate then set aside.

Turn heat down to medium then add peppers and shallots to pan. Season with salt and pepper then saute for 5 minutes or until peppers are crisp-tender. Add garlic then saute for 30 more seconds.

Add chicken broth, marinara sauce, Italian seasoning, and red chili pepper flakes to pan then turn heat up to bring mixture to a boil. Add pasta then shake pan to cover all the pasta with liquid and then nestle sausages on top. Place a lid on top then reduce heat to medium-low and simmer for 8-10 minutes or until pasta is just under al dente, shaking the pan every so often to make sure the pasta is cooking evenly. Don’t let the pasta reach al dente as it still has a few more minutes to cook.

Arrange cheese slices on top of pasta and sausages then place lid back on top. Let cheese melt then remove pan from heat and let sit with the lid off to thicken slightly for a few minutes before serving.