Season and prepare the chicken. Pat each breast dry with kitchen paper, then season both sides generously with salt and pepper. Drying the surface matters more than people realise, because moisture is the enemy of a golden crust. Set them on a plate while you slice the mushrooms.

Sear the chicken. Heat 1 tablespoon of the olive oil in a large frying pan over medium-high heat until it shimmers and a drop of water flicked in sizzles instantly. Lay the breasts in, leaving space between them, and cook for 5 to 6 minutes per side. You're looking for a deep golden-brown crust and juices that run clear when you press the thickest part. The internal temperature should read 74°C. Transfer to a plate and tent loosely with foil.

Brown the mushrooms. Add the remaining oil and the butter to the same pan. Once the butter foams, tip in the mushrooms in a single layer. Resist stirring for the first 3 minutes. They'll release water, then reabsorb it, then start to squeak and turn nutty brown at the edges. That squeak is your cue that they're properly caramelised, which takes about 7 minutes total.

Build the base. Add the onion and cook for 3 minutes until translucent and soft, scraping up the browned bits from the bottom of the pan as you go. Stir in the garlic, thyme and oregano and cook for just 45 seconds. The kitchen should smell warmly garlicky, but not sharp or acrid, which means you've gone too far.

Thicken and deglaze. Sprinkle the flour over everything and stir constantly for 1 minute, coating the mushrooms and onions. Pour in the chicken stock in a steady stream, stirring as you go, and let it bubble for 2 minutes until it thickens enough to coat the back of your spoon.

Finish the sauce. Lower the heat to medium-low and stir in the cream and Parmesan. Let it simmer gently for 3 minutes. The sauce should look glossy and pale ivory, and it will thicken further as it sits. Taste and adjust the salt, keeping in mind that Parmesan is salty.

Return the chicken. Nestle the breasts back into the pan along with any juices that collected on the plate. Spoon sauce over the top and simmer for 3 to 4 minutes so the chicken warms through and absorbs some of the garlicky cream.

Rest and serve. Take the pan off the heat and let everything sit for 5 minutes. Scatter over the fresh parsley and serve straight from the pan.