So these cherries have pits!! My kitchen is full of gadgets but not a cherry pitter. Normally when I see how you can take an ordinary item and make something else useful out of it, I always think what a great idea but never seem have a need for it. Who knew a paper clip would made a great cherry pitter?
Combine the first 5 ingredients in a saucepan and bring to a boil over medium heat. Boil 5 minutes, stirring occasionally. Stir in the cherries and bring to a boil over medium low heat. Cook 10 - 15 minutes, stirring often. Strain the mixture and return to the pan. Combine the cornstarch and water. Stir into the sauce and bring to a boil, stirring constantly for 5 minutes.
Brush on chicken breasts during the last few minutes of cooking. Watch carefully, since the sauce is sweet, it will burn easily.