2 tablespoons balsamic vinegar or 1 1/2 tablespoons red wine vinegar
1 teaspoon Dijon mustard
1/4 cup chopped fresh basil (optional)
Directions
Heat oil in heavy large skillet over medium-high heat. Add onion and garlic and sauté until just tender, about 4 minutes. Add chicken and cook until chicken is brown, stirring constantly, about 3 minutes. Stir in vinegar and mustard. Continue cooking until chicken is tender and cooked through, stirring constantly, about 3 minutes. Season with salt and pepper. Sprinkle with basil if desired.