Heat oil in a large dutch oven on mdeium high til shimmering. Add sausages and brown on all sides- 5-8 minutes. Remove the sausages from the pot once browned, slice them on a bias and return them to the pot for another 2 minutes to brown the faces as well
Season the chicken liberally in salt and pepper. Once the sausages are done, remove them from the pot with a slotted spoon and set aside. Add the chicken, stirring to coat in sausage grease and cook until almost no longer pink. 3-5 minutes.
Remove the chicken from the pot with a slotted spoon and set aside.
Add the onions, peppers and celery and saute for 2-4 minutes til beginning to soften, then stir in the garlic and cook another 1-2 minutes until fragrant.
Add the tomato paste, cajun seasoning, paprika, oregano and stir to combine. Continue to saute on medium high for another 2-3 minutes until fully fragrant.
Add the tomatoes, chicken and sausage to the pot. Combine everything in the pot with a flat bottom spoon, scraping the bottom vigorously to get up all the tasty brown stuff (the fond).
Add the chicken broth and rice, then stir to fully combine. Bring the heat up to high until the liquid is boiling, then reduce to medium-low and simmer uncovered for 15 minutes or until the rice is done.
There should still be some liquid when you're done, remove the pot from the heat and the rice will continue to soak up the liquid. Serve garnished with fresh sliced green onion.