1. Heat the olive oil in a large Dutch oven or heavy-bottomed pot over medium-high heat. Add the chicken pieces and cook until browned on all sides, about 5-7 minutes. Remove the chicken from the pot and set aside. Add the sliced smoked sausage to the same pot and cook until lightly browned, about 3-5 minutes. Remove the sausage and set aside with the chicken.

2. Reduce the heat to medium. Add the chopped onion, green bell pepper, and celery to the pot. Cook, stirring occasionally, until the vegetables soften, about 5-7 minutes. They should be translucent and fragrant.

3. Stir in the minced garlic, dried oregano, smoked paprika, cayenne pepper, black pepper, and salt. Cook for 1 minute more, stirring constantly, until the spices are fragrant. This step really helps to bloom the flavors.

4. Pour in the undrained diced tomatoes, Rotel diced tomatoes with green chilies, and chicken broth. Bring the mixture to a gentle simmer, scraping up any browned bits from the bottom of the pot.

5. Add the uncooked long-grain white rice to the pot and stir well to combine. Return the browned chicken and sausage to the pot, nestling them into the liquid and rice mixture.

6. Bring the mixture back to a simmer, then reduce the heat to low, cover the pot tightly, and cook for 20-25 minutes, or until the rice is tender and most of the liquid has been absorbed. Avoid lifting the lid too often during this time to allow the rice to cook evenly.

7. Once the rice is cooked, remove the pot from the heat and let it sit, covered, for 5-10 minutes. This allows the rice to steam and become fluffy. Fluff the jambalaya gently with a fork before serving. Garnish with fresh chopped parsley, if desired.