Begin by heating 1 tablespoon of oil in a large saucepan over medium-high heat. Season the chicken with cajun seasoning, then add it to the hot pan. Cook for about 2–4 minutes per side, or until the chicken turns a golden brown. Remove the chicken from the pan and set aside.

In the same saucepan, melt 1 tablespoon of butter over medium heat. Add diced onion, celery, and bell pepper. Sauté the vegetables for about 5–7 minutes until tender and fragrant.

Stir in chopped garlic, chopped thyme, and an additional tablespoon of cajun seasoning into the softened vegetables. Cook for another minute, stirring frequently.

Pour in chicken broth along with the cooked chicken, diced tomatoes (if using), and Worcestershire sauce. Add the pasta to the pot; bring the mixture to a rolling boil, then reduce to a simmer and cook for about 7 minutes or until the pasta is al dente.

Once the pasta is tender, remove the cooked chicken from the pot. Shred or slice the chicken into bite-sized pieces, then return it to the soup.

Turn off the heat and gently stir in the heavy cream and grated Parmigiano Reggiano until the cheese melts into the broth, creating a luxurious texture.

Add lemon juice and sprinkle in chopped parsley and sliced green onions, if desired. Season the soup with cayenne, salt, and pepper to taste.