Prepare the Chicken: Place a chicken breast between two sheets of baking parchment or in a zip-top bag. Using a rolling pin or meat mallet, gently pound the chicken until it is an even thickness of about 1-1.5cm. This technique, explained well by the team at Serious Eats, ensures it cooks evenly. Season both sides generously with salt and pepper.

Set Up Your Breading Station: You'll need three shallow dishes. Put the 75g of plain flour in the first, the 2 beaten eggs in the second, and the 150g of Panko breadcrumbs in the third. Season the flour and breadcrumbs with a little more salt and pepper.

Coat the Chicken: Working with one piece at a time, dredge a chicken breast in the flour, shaking off any excess. Then, dip it into the egg, ensuring it's fully coated. Finally, press it firmly into the Panko breadcrumbs, covering it completely. Set the coated chicken aside on a plate.

Cook the Schnitzel: Heat the 3 tbsp of oil in a large frying pan over a medium-high heat. Carefully place two chicken schnitzels in the pan (don't overcrowd it). Fry for 3-4 minutes on each side, until they are a deep golden brown and cooked through. Remove from the pan and place on a wire rack to keep them crispy. Repeat with the remaining chicken, adding a splash more oil if needed.

Start the Sauce Base: Reduce the heat to medium. Add the 1 tbsp of butter and 1 tbsp of olive oil to the same pan. Add the finely diced onion and cook for 5-7 minutes, until softened and translucent. Add the minced garlic and cook for another minute until fragrant.

Brown the Mushrooms: Add the sliced mushrooms to the pan. Turn the heat up slightly and cook for 6-8 minutes, stirring occasionally, until they have released their liquid and have started to turn a lovely golden brown. Don't rush this part!

Deglaze and Thicken: Pour in the 50ml of white wine to deglaze the pan, using a wooden spoon to scrape up any flavourful browned bits from the bottom. Let it bubble and reduce by about half. Sprinkle over the 1 tbsp of flour and stir continuously for one minute. What works best for me is to really cook out that flour taste before adding any more liquid.

Build the Creamy Sauce: Gradually pour in the 300ml of chicken stock, whisking as you go to prevent lumps. Bring it to a gentle simmer, then pour in the 150ml of double cream.

Finish and Season: Let the sauce simmer gently for 3-4 minutes until it has thickened to a consistency that coats the back of a spoon. Stir in the 1 tsp of Dijon mustard and the chopped fresh parsley. Taste and season with salt and pepper as needed.

Serve Immediately: Place a crispy chicken schnitzel on each plate and generously spoon the hot, creamy mushroom sauce over the top.