Classic Chicken Marsala

300 g cremini mushroom, sliced

1 shallot, finely chopped

2 garlic, minced

30 ml parsley, chopped, for garnish

600 g chicken breast, pounded to 1/2-inch thickness

30 g unsalted butter, divided

120 ml heavy cream

60 g all-purpose flour, for dredging

30 ml olive oil

240 ml marsala wine, dry

240 ml chicken stock

5 ml kosher salt

2 ml black pepper, freshly ground