Bring a large pot of water to boil for the pasta. Meanwhile, start the sauce:

Heat a large pan over medium high heat.

Add the butter and oil to the pan.

When the oil and butter have melted and are hot, add the chicken, mushrooms, onion, and thyme; season with salt and pepper. If the pan is too hot then drop the heat to medium.

Sauté until the chicken is browned and the mushrooms have given off their water.

Turn the heat to high and add the garlic, sauté for about 30 seconds.

Add the white wine and scrape the bottom of the pan with a wooden spoon to release any flavours (deglazing). Let the wine boil for about one minute to let the alcohol cook out.

Drop the heat to medium high and add the stock.

When the pan has come back up to a boil, add the Dijon mustard and mix well.

Cook the pasta one minute less then the cooking instructions indicate, drain the pasta when it’s cooked.

Turn the heat off the pan and let it sit for a minute (just to let the temperature drop a bit).

Discard the thyme stems.

Add the cream and mix well.

Add the pasta to the pan and mix well.

Return the pan to low heat and let it sit for one or two minutes, until the pasta is cooked through and some of the liquid has been absorbed.

Stir in some Parmesan cheese if using; I added ¼ cup (that’s only a tablespoon per person!).

Taste and adjust seasoning.

Serve immediately.