Heat olive oil in a large skillet over medium-high heat.
Add the sliced chicken sausage to the skillet and cook for 5-6 minutes, stirring occasionally, until browned and cooked through. Remove sausage from skillet and set aside.
In the same skillet, add the diced onion and cook for 3 minutes until softened.
Add the minced garlic, diced red bell pepper, and sliced mushrooms to the skillet. Cook for 4-5 minutes until vegetables are tender.
Stir in the dried Italian seasoning, smoked paprika, and crushed red pepper flakes. Cook for 1 minute until fragrant.
Pour in the chicken broth and bring to a simmer, scraping up any browned bits from the bottom of the skillet.
Reduce heat to medium-low and stir in the heavy cream and grated Parmesan cheese. Cook for 3-4 minutes until the sauce thickens slightly.
Return the cooked chicken sausage to the skillet and stir to combine. Cook for an additional 2 minutes to heat through.
Season with salt and freshly ground black pepper to taste.
Remove from heat and garnish with chopped fresh parsley before serving.