Heat 1 tbsp of olive oil in a large pot over medium-high heat. Brown the sliced beef sausage and diced chicken breast for 5 to 7 minutes. Remove and set aside.
In the same pot, add remaining 1 tbsp olive oil. Saute the diced red bell pepper, green bell pepper, onion, and celery for 5 minutes until softened.
Stir in the Cajun seasoning, long-grain white rice, and crushed tomatoes. Cook for 2 minutes to toast the rice slightly.
Pour in the chicken broth and return the cooked chicken and beef sausage to the pot. Bring to a boil, then reduce heat to low, cover, and simmer for 20 minutes.
Remove the lid, stir in the shrimp, cover again, and cook for an additional 5 minutes until shrimp are pink and cooked through.
Remove from heat, let it rest for 5 minutes, garnish with chopped parsley, and serve warm.