Melt 2 tablespoons of butter in a large Dutch oven over medium-high heat.

Add 1 diced onion, 1 diced celery stalk, and 1 diced bell pepper to the Dutch oven, and sauté for about 5 minutes.

Stir in 3 minced garlic cloves and half of the Cajun seasoning, and sauté for another 30-60 seconds.

Pour in 4 cups of chicken stock and 1 can of diced tomatoes, then bring to a low boil and simmer for about 10 minutes.

Season 1 pound of sliced chicken breasts with the remaining Cajun seasoning and sear in a skillet for 3-5 minutes per side.

Add the seared chicken to the Dutch oven and pour in 1 cup of heavy cream, then simmer for another 3-5 minutes.

Taste the soup and adjust seasoning if needed, serve hot garnished with chopped green onions or parsley.