Milano's Chicken with Mustard Sauce

Ingredients:
4 skinless, boneless chicken breasts
6 Tablespoons olive oil
1/4 cup chopped shallots
8 ounces fresh mushrooms, chopped
1 pint heavy cream
3 Tablespoons whole grain Dijon mustard
Salt and Pepper to taste
Wash chicken breasts and pat dry with a paper towel. If desired, tenderize and flatten the breasts to a uniform thickness to allow them to cook evenly by placing them between two sheets of plastic wrap and pounding with a mallet until evenly flattened. I did not do this because mine were all the same size.
Heat 3 Tablespoons of the olive oil over medium-high heat in a large saute' pan. Maintain the heat at a fast sizzle, but do not let it smoke. Saute' the breasts until browned on one side, about 3-4 minutes. Turn with tongs and cook on the other side until meat feels firm when pressed and juices begin to emerge around the edges, about 3-4 min. more. (Done at 160 degrees). Remove the breasts to a warm platter and keep warm in oven set at 200 degrees. Add the remaining oil to the pan, allow it to heat, then add the shallots and mushrooms and saute' for 3-4 minutes, stirring frequently. Mix the heavy cream and mustard together, then add to the pan. Reduce heat slightly and cook, stirring and scraping up the congealed browned bits with a wooden spoon, until the sauce has reduced about two thirds and thickened to desired consistency. Season to taste with salt and pepper. Serve the chicken breasts immediately on warm plates, topped with the mushroom cream sauce.