Gather and prep ingredients: chop vegetables, slice sausage, cube chicken, and rinse the rice.
Heat the oil in a large pot over medium-high heat. Brown the chicken on both sides. Transfer to a plate.
Add the sausage to the pot and sear until lightly crisp. Remove and set with the chicken.
Sauté onion, bell pepper, and celery until soft. Stir in garlic and tomato paste; cook until fragrant.
Stir in the rice, Cajun seasoning, paprika, thyme, cayenne, salt, and pepper. Toast for 1 minute.
Pour in broth, diced tomatoes, and Worcestershire. Scrape the bottom clean. Return chicken and sausage to the pot.
Bring to a boil, then reduce heat. Cover and simmer gently until rice is nearly tender, about 20 minutes.
Nestle shrimp on top. Cover and cook until pink and opaque, 5 to 7 minutes.
Turn off heat. Rest 5 minutes, then fluff rice and fold in green onions and parsley. Adjust seasoning.