Heat the oil in a large, heavy skillet over high heat. Season the chicken breasts with Essence, then add the chicken breasts and cook for 3 to 3 1/2 minutes on each side. Transfer to a platter and keep warm.
Wipe the skillet with paper towels and return to the stove. Heat the butter in the skillet over medium heat. Add the onions and cook, stirring, for 3 minutes. Add the garlic and cook, stirring, for 30 seconds. Add the ham and cook, stirring occasionally, for 3 minutes. Add the mushrooms and continue cooking for 5 minutes. Add the peas and cook for 2 minutes. Add the Brabant Potatoes, salt, pepper and the chicken breasts, and cook for 1 minute.
To serve, put about 3/4 cup of the ham-vegetable mixture on each dinner plate, and top with a chicken breast. Spoon about 1/4 cup of the BČarnaise Sauce over the chicken.
Yield: 4 servings