Heat your pot or a deep skillet over medium heat. Toss in sausage medallions and cook until brown and a little crispy, about 5 minutes.
Add the sliced mushrooms, bell peppers, and garlic. Stir occasionally and cook about 4 minutes until soft and fragrant.
Pour in gluten-free penne pasta followed by diced fire-roasted tomatoes. Add chicken broth and sprinkle Cajun seasoning. Stir well.
Bring to a boil, then lower heat to medium-low and cover with lid. Let simmer, stirring occasionally, until pasta is tender and broth mostly absorbed, about 15 minutes.
Lower heat, stir in cream cheese until melted completely. Simmer 2-3 more minutes to thicken sauce.
Taste pasta and add salt if needed. Garnish with chopped parsley and red pepper flakes if desired. Serve hot.
Notes
Serve hot and enjoy a creamy, spicy one-pot pasta. Cleanup is easy with just one pot used.