In a shallow bowl or plate combine the flour and Essence and stir to combine thoroughly. Quickly dredge the chicken breast halves in the seasoned flour mixture, shaking to remove any excess flour.
Heat the oil in a large skillet over medium-high heat until very hot but not smoking. Add 1 tablespoon of the butter and cook the chicken breasts until golden brown on both sides, about 3 minutes per side. Transfer to a plate and set aside. Add 1 tablespoon of the remaining butter to the pan and add the mushrooms. Cook, stirring frequently, until mushrooms are golden brown around the edges and have given off their liquid. Add the Marsala wine and bring to a boil, scraping to remove any browned bits from the bottom of the pan. When the wine has reduced by half, add the chicken stock and cook for 3 minutes, or until the sauce has thickened slightly. Lower the heat to medium and return the chicken breasts to the pan and continue to cook until they are cooked through and the sauce has thickened, about 5 to 6 minutes. Swirl in the remaining 2 tablespoons of butter, add salt and pepper, to taste. Garnish with chopped chives and serve immediately.
Essence (Emeril's Creole Seasoning):
Yield:about 2/3 cup
Combine all ingredients thoroughly and store in an airtight jar or container.
Recipe from "New New Orleans Cooking", by Emeril Lagasse and Jessie Tirsch. Published by William and Morrow, 1993.