Cook the Pasta & Asparagus: Bring a large pot of salted water to a boil. Add the penne and cook according to the package instructions until al dente. For the final 3 minutes of cooking time, add the chopped asparagus to the pot. Before draining, reserve about 250ml (a large mugful) of the starchy pasta water. Drain the pasta and asparagus and set aside.

Sear the Chicken: While the pasta is cooking, heat 1 tablespoon of olive oil in a large, deep frying pan or sauté pan over a medium-high heat. Season the cubed chicken with salt and pepper, then add it to the hot pan in a single layer. Cook for 5-7 minutes, turning occasionally, until golden brown on all sides and cooked through. Remove the chicken from the pan and set it aside on a plate.

Sauté the Aromatics: Reduce the heat to medium and add the remaining olive oil and the butter to the same pan. Once the butter is melted, add the finely chopped onion and cook for 4-5 minutes, stirring occasionally, until it has softened and become translucent.

Brown the Mushrooms: Add the sliced mushrooms to the pan. Turn the heat up slightly and cook for 5-6 minutes, stirring infrequently, until they have released their moisture and are nicely browned. This step is crucial for developing their deep, earthy flavour. Add the minced garlic and cook for one more minute until fragrant.

Build the Sauce: Pour the chicken stock into the pan to deglaze it, using a wooden spoon to scrape up any flavourful browned bits stuck to the bottom. Let it bubble and reduce for a minute.

Make it Creamy: Stir in the double cream and bring the sauce to a gentle simmer. Let it bubble away for 2-3 minutes to thicken slightly.

Add the Cheese: Reduce the heat to low. Add the freshly grated Parmesan cheese and stir continuously until it has completely melted into the sauce, creating a smooth and glossy consistency. I find that turning the heat right down before adding the cheese is the best way to prevent it from splitting.

Combine Everything: Return the cooked chicken to the pan, along with the drained penne and asparagus. Toss everything together gently until the pasta and other ingredients are fully coated in the creamy sauce.

Adjust and Season: If the sauce seems a little too thick, stir in a splash of the reserved pasta water until it reaches your desired consistency. Season generously with salt and black pepper to taste. Stir through most of the chopped fresh parsley.

Serve Immediately: Divide the Mushroom Asparagus Chicken Penne among four warm bowls. Garnish with the remaining fresh parsley and an extra grating of Parmesan cheese.