Heat olive oil in a large, heavy-bottomed pan or Dutch oven over medium-high heat. Add chicken pieces and cook for 5-6 minutes until golden brown on most sides. Remove chicken and set aside. Add sliced sausage to the same pan and brown for 3-4 minutes until slightly caramelized.

Without cleaning the pan, add diced onion, bell pepper, and celery to the sausage fat. Cook for 6-8 minutes, stirring occasionally, until vegetables soften and the onion becomes translucent. Add minced garlic and cook for another minute until fragrant.

Stir in the rice, coating each grain with the flavorful vegetable mixture. Add paprika, oregano, and cayenne pepper, stirring constantly for about 2 minutes until the rice looks slightly toasted and the spices bloom.

Pour in chicken broth and add drained diced tomatoes, bay leaves, and the browned chicken back to the pan. Season generously with salt and pepper. Bring to a rolling boil, then reduce heat to low, cover tightly, and simmer for 18-20 minutes without lifting the lid.

Remove from heat and let stand, covered, for 5 minutes. Remove bay leaves, fluff gently with a fork, and garnish with fresh green onions before serving.