Cook the Pasta: Bring a large pot of salted water to a rolling boil. Add the pasta and cook according to package directions until al dente. Just before draining, reserve about 200ml (a mugful) of the starchy pasta water. Drain the pasta in a colander and set aside.

Season and Cook the Chicken: While the pasta is cooking, place the chicken chunks in a bowl. Add 1 tablespoon of the Cajun seasoning and a pinch of salt. Toss well to coat everything evenly. Heat the olive oil and butter in a large, deep frying pan over a medium-high heat. Add the chicken and cook for 5-7 minutes, turning occasionally, until golden brown and cooked through. Remove the chicken from the pan with a slotted spoon and set it aside on a plate.

Sear the Prawns: In the same pan, add the peeled prawns. Cook for 1-2 minutes on each side until they turn pink and opaque. Be careful not to overcook them. Remove the prawns from the pan and add them to the plate with the chicken.

Sauté the Vegetables: Reduce the heat to medium. Add the chopped onion and sliced bell peppers to the pan. Cook for 5-6 minutes, stirring often, until they have softened. Add the minced garlic and cook for another minute until fragrant.

Build the Creamy Sauce: Sprinkle the remaining tablespoon of Cajun seasoning over the vegetables and stir for 30 seconds to toast the spices. Pour in the chicken stock to deglaze the pan, scraping up any tasty browned bits from the bottom. Stir in the tomato purée, then pour in the double cream. Bring the sauce to a gentle simmer.

Combine and Finish: Reduce the heat to low and stir in the grated Parmesan cheese until it melts into a smooth, velvety sauce. Return the cooked chicken and prawns to the pan. Add the drained pasta and toss everything together. If the sauce is too thick, add a splash of the reserved pasta water to loosen it to your desired consistency.

Serve: Let the pasta sit in the sauce for a minute to absorb the flavours. Check for seasoning and add more salt and pepper if needed. Serve immediately, garnished with a generous scattering of fresh chopped parsley.