I started with a recipe found on the internet that reportedly was a favorite menu choice from "Tavern on the Green" restaurant in New York City. I don't know whether it's the actual recipe used at that restaurant, but it's quite good anyway. However, I made a few changes to increase the lemon flavor because the original recipe used only dried lemon zest, and I prefer fresh lemons which seem to produce a tangier burst of lemon flavor.
For wine suggestions, their servers recommended serving this dish with a crisp chardonnay.
Mix together the flour, salt, and pepper in a shallow dish; set aside. In another shallow dish, beat eggs and lemon juice together; set aside.
Pound chicken breasts between two sheets of plastic wrap to make uniform thickness for even cooking.
Heat butter in a large skillet.
While butter is heating, dredge chicken breasts in the flour mixture. Once the butter is melted, dip floured chicken breasts in the egg mixture, and sauté chicken breasts in the hot butter for three minutes. Reduce heat to medium, turn chicken over and add the shallots and garlic, and cook one more minute. Add wine and stir for about 2 minutes to deglaze the skillet. Season with salt and pepper if desired. Stir dijon mustard into the pan sauce and let sauce cook for two minutes to reduce slightly Add heavy cream to sauce and cook for another two minutes to thicken sauce slightly.
To Serve - Place chicken on individual plates or place all on a large platter. Spoon pan sauce over each chicken breast. Garnish each serving with a fresh lemon slice, and serve immediately.