Heat a large pot over medium heat and add the Andouille sausage. Cook until browned, about 5 minutes.
Add the diced chicken thighs and cook until browned on all sides, about 7 minutes.
Stir in the chopped onion, bell pepper, and celery. Cook for about 5 minutes until softened.
Add garlic and cook for an additional minute until fragrant.
Stir in the diced tomatoes, Cajun seasoning, salt, and pepper. Cook for 2 minutes.
Pour in the chicken stock and bring to a boil.
Add the rice, reduce the heat to low, cover the pot, and simmer for 20 minutes.
Remove from heat and let it sit, covered, for 5 minutes before fluffing with a fork.
Garnish with chopped green onions before serving.