For The Mustard Butter: Combine the butter, shallot, pepper, salt, thyme and mustards in a bowl. Beat until light and fluffy.
Shape the butter into a 7-inch log on waxed paper. Wrap in the waxed paper. Chill until firm.
For The Chicken: Rinse the chicken and pat dry. Combine the sage, oregano, ginger, rosemary, marjoram, thyme, celery seeds, pepper and salt in a shallow bowl. Coat the chicken in the herb mixture.
Saute the chicken in butter in a large skillet for 5 minutes on each side or until cooked through.
Arrange the chicken on serving plates. Serve with a slice of mustard butter on top.
Authors Note: The mustard butter may he made up to two weeks in advance and kept chilled.