Remove the chicken from the fridge 20-30 minutes before you plan to cook and season well with salt. Leave to come to room temperature.
Heat the oil over medium-high flame in a large skillet or frying pan. When the oil is hot, dredge both sides of the chicken pieces in the seasoned flour, shake off the excess, and add to the pan.
Fry until golden, flip and repeat on the other side. Do this in batches to keep from overcrowding the pan. Remove the chicken to a large platter in a single layer to keep warm.
Lower the heat to medium and add the Pancetta to the same pan and cook until crisp. Using a slotted spoon, remove the Pancetta from the pan onto a plate lined with paper towels.
Add the onions to the pan and cook until softened. Add the mushrooms and saute until they are nicely browned and their moisture has evaporated.
Add the garlic and cook another minute. Season with salt and pepper and coat in 1 tablespoon of flour.
Raise the heat to high. Add the Marsala to the pan, bring to a boil and cook down for a minute to cook out the alcohol. Add the chicken stock and cook for another 3 minutes to thicken the sauce slightly.
Stir in the butter and parsley. Return the chicken and Pancetta to the pan; simmer for 1 to 2 minutes to heat the chicken through.
Taste for seasoning and season with salt as needed before serving.
Notes
When pan-frying the chicken, don’t skimp on the oil. You need enough oil to get a golden-brown crust.
Remove the chicken from the refrigerator about 20 minutes before you’re ready to cook. This helps the chicken to cook evenly.
Keep the heat at a steady, high temperature when pan-frying the chicken. This limits how much the flour absorbs the oil, which will cause a soggy finish.
Don’t overcrowd the pan. Overcrowding causes the chicken to steam instead of fry. It’s better to fry in batchesinstead.
If the Pancetta releases a lot of fat, drain the pan of all but a tablespoon before moving on.
If you prefer a creamy sauce, add a half cup of heavy cream when you add the stock to the pan.