Cut the Chestnut Mushroom in half (or quarters) and set aside.
Apply the 20 sprays of oil spray to a large frying pan, large enough to accommodate the two chicken breasts comfortably (if you have one with a matching lid even better, as you’ll need it later); once the oil is warm, add the two breats and cook on high flame for one minute one each side, so to give it a bit of color, then lower the flame to medium heat.
Add the mushrooms to the pan and cover with the lid; if the pan you are using doesn’t have a lid, you can either use one from a larger pan or silver foil. After one minute on medium heat, lower to low and allow to cook for about 5 minutes.
While the chicken and mushrooms are cooking, in a small bowl pour the milk and warm it up in the microwave for about 30 seconds (if using a milk jug on the gas, just make it slightly warmer than room temperature) then add the cream cheese and mix well. There will be a few knots of cheese in the milk, which should ‘melt away’ while cooking later.
Once the mushrooms and chicken are nearly ready (90%) add the seasoning (salt and pepper) and some parsley if wanted. Mix well and increase the heat to medium.
Add the milk-cheese mixture (light cream) to the pan with the chicken and mushrooms and mix well, especially around the mushrooms and cover the pan with the lid again for a further 2-3 minutes.
At this point both the chicken and the mushrooms should be cooked, so mix well, cover with the lid again and turn off the heat/gas. Let is sit for 5 minutes, then plate and serve!