Preheat your oven to 180C/350F, suitable for all oven types.
Warm the vegetable oil in a large skillet or Dutch oven over medium-high heat (Note 4).
Add the bacon and cook for about 30 seconds to start rendering the fat, then introduce the sausage slices. Cook until the sausages are nicely browned, roughly 3 minutes, and then transfer them to a bowl.
Place the chicken pieces into the pan and cook until they achieve a golden color on the outside. The chicken doesn't need to be fully cooked inside at this stage. Transfer to the bowl with the bacon and sausage.
Sear the prawns/shrimp in the same pan for about 1.5 minutes on each side, then set them aside in a separate bowl to be used later.
Add the butter to the pan, followed by the minced garlic, chopped onion, celery, and bell peppers. Cook for 3 to 4 minutes until they begin to soften.
Stir in the rice, ensuring each grain is coated with the oil.
Pour in the chicken broth, then add the tomato paste, crushed tomatoes, thyme, and the prepared seasoning mix.
Stir everything thoroughly, then reintroduce the chicken, sausages, and bacon (along with any accumulated juices) to the pan.
Once bubbles appear across most of the surface, give it another good stir. Ensure the rice is fully submerged, cover the pan with a lid, and transfer it to the preheated oven. (Refer to the video if needed).
Bake for 20 minutes. Remove the lid and taste a few grains of rice (caution: it's hot!). If the rice is almost done (see Note 5 for the desired consistency), proceed to the next step. If the rice is still firm in the center, continue baking, checking every 5 minutes. Most ovens will require about 30 minutes of total cooking time (refer to Note 7).
Add the prawns/shrimp and green onions, stir gently but swiftly, cover the pan again, and return it to the oven for an additional 3 minutes to heat the prawns.
Take the pan out of the oven (refer to the video for the finished consistency), gently fluff the mixture, and serve. Garnish with extra green onions if desired.