Note: To make clarified butter, slowly melt a stick of unsalted butter until the milk solids melt to the bottom of the pan; skim foam off the top and use only the clear golden liquid.
Pound chicken breasts between two sheets of plastic wrap to make uniform thickness for even cooking.
Dredge chicken breasts in flour, shaking off excess.
Heat clarified butter in sauté skillet over medium-high heat.
Place chicken in pan and sauté until cooked halfway through, about three minutes; reduce heat to medium.
Turn chicken over and add minced shallots and garlic; cook for one minute until you can smell the aroma of garlic, and then add wine to deglaze pan.
Season with salt and pepper.
Add mustard and stir into sauce; let sauce cook for two minutes to reduce, and then add heavy cream.
Let sauce cook for another two minutes to thicken sauce slightly.
Serve with chardonnay.