Easy Chicken Marsala

INGREDIENTS
CHICKEN:
4 boneless skinless chicken breasts halves, sliced horizontally in half to make 8 cutlets
1 teaspoon kosher salt
1 teaspoon ground black pepper
1/2 teaspoon garlic powder
2 tablespoons olive oil, divided
1 tablespoon unsalted butter divided
MARSALA SAUCE:
2 tablespoons unsalted
1 small onion, diced
3 cloves garlic, minced
1 pound fresh mushrooms, sliced
1/4 cup dry marsala wine
1 cup chicken stock
1/2 cup heavy cream
Generous pinch of salt and ground black pepper, or to taste
1 tablespoon flour or any other thickening agent + water
1 tablespoon dried parsley or freshly chopped

INSTRUCTIONS
CHICKEN:
Cut each chicken half in half horizontally. Season it with some salt and pepper on both sides and garlic powder.
Heat oil and butter in a large frying pan or a skillet over medium-high heat.
Cook the chicken cutlets until golden-brown on both sides, about 2 to 3 minutes per side.
If your skillet/pan is smaller then cook the chicken in batches so the pan is not overcrowded.
Transfer to a platter and cover with a lid or aluminium foil until ready to use.
MUSHROOM SAUCE:
In the same large frying pan or a skillet with grease leftover from the chicken, add more butter.
When the butter has melted add onion and garlic and stir well, then add sliced mushrooms and cook for a couple of minutes until browned.
Scrap any of the leftover chicken bits off the bottom of the pan while mixing it.
Pour in the dry marsala wine and the broth. Simmer until reduced by half and starting to thicken, about 10 minutes on low temperature.
Pour in the cream stir to combine.
Take 2 tablespoons of flour or any other thicker such as cornstarch and mix with 4 tablespoons of water.
Mix until smooth. Add thickener to the sauce and mix well until it starts to get thicker, a few minutes.
The sauce will continue getting thick even off heat, just keep that in mind.
If you see that it gets too thick stop adding more and you can always add more liquid to make it thinner.
Return the chicken into the sauce.
Add all those chicken drippings as well.
Cook until the sauce coat all the chicken, reheated and gets thicker and shiny.
Garnish with chopped parsley and serve.