Place chicken between 2 sheets of waxed paper; pound to 1/4-inch
thickness, using a meat mallet or rolling pin.
Place chicken in a shallow baking dish. Combine brown sugar, mustard,
bourbon, green onions, salt, and Worcestershire sauce; stirring
well.
Brush mustard mixture evenly over both sides of chicken breast
halves.
Cover and marinate in refrigerator for 1 hour.
Remove chicken from marinade, reserving marinade.
Combine butter and oil in lg. skillet, and place over med-high
heat.
Saute chicken 3 to 4 mins. on each side or until done. Remove
chicken to
a serving platter, and keep warm. Drain and discard pan drippings.
Add
reserved marinade to a skillet; bring to a boil, stirring constantly.
Pour sauce over chicken.
Source - "Gatherings" by the Junior League of Milwaukee, WI
As posted by S. Woodward