Cut half the butter into tablespoon-size bits and set it aside to soften. Clarify the remainder of the butter and strain it.
Reduce the chicken stock by half by boiling.
Trim each breast and cut crosswise into equal halves. Pound if necessary to get even thickness for cooking. Coat each piece with chopped pecans.
Saute the chicken in the clarified butter about 4 minutes on each side. Set each finished piece on a serving platter and keep warm while you make the sauce.
Add the bourbon to the hot pan and boil it down by half. It's OK if there are pecan bits in there. When it has boiled down by half, flame it (carefully - there's still a lot of alcohol in there) and stir until the flames subside.
Add the hot stock and bring to a boil again.
Add the herbs.
Enrich the sauce: Stir in the softened butter tablespoon by tablespoon, letting each one melt before adding the next.
Dress the chicken with the sauce and serve at once.
Darker maple syrup adds more flavor to complement the whiskey than the lighter, fancier grades do.
You get better pecan flavor if they are not too uniformly small - leave some bigger bits.