Dice the onions, peppers and celery - I leave the peppers medium-sized but cut the rest relatively small. Dice the chicken and thinly slice the sausage.
Warm the oil in a wide, heavy based dish then add the onion, pepper, celery and garlic. Cook, stirring now and then, until just soft (3-5min).
Add the chicken and sausage then cook, stirring regularly, until the chicken is just cooked through. Add the tomatoes, stock, rice, bay leaf, thyme, oregano, paprika and cayenne. Bring to a simmer then cover, reduce the heat and leave approximately 20 minutes until the rice is just cooked. You may need to stir now and then, depending on your dish.
Add the shrimp, pressing them under the rice mixture to help them cook through. Turn them over if needed and once cooked through, serve.