Stir in 1 1/2 cups chicken broth, cream or half and half (optional), Dijon mustard
and balsamic vinegar. Whisk cornstarch with remaining 1/2 cup chicken broth and add to skillet. Bring to a boil then reduce to a simmer, stirring occasionally until sauce has thickened. Add chicken back to skillet, stir in half the bacon and leave the rest to garnish.