In a large pot or deep skillet, heat the olive oil over medium heat. Add the sliced sausage and cook until browned, about 5 minutes. Remove the sausage and set aside.

In the same pot, add the diced onion and bell pepper. Sauté for about 3-4 minutes until softened. Add the minced garlic and cook for an additional 1 minute.

Stir in the Cajun seasoning, paprika, black pepper, and salt. Cook for another minute to toast the spices.

Add the penne pasta, diced tomatoes (with their juice), and chicken broth to the pot. Bring to a boil, then reduce the heat to a simmer. Cover and cook for 12-15 minutes, stirring occasionally, until the pasta is al dente and most of the liquid is absorbed.

Stir in the heavy cream and cooked sausage. Cook for another 2-3 minutes until heated through. Remove from heat and stir in the shredded cheddar cheese until melted and creamy.

Serve immediately, garnished with sliced green onions.