Heat the oil in a 10-inch skillet over medium-high heat. Add the chicken and cook for 10 minutes or until it's well browned on both sides. Add the garlic and cook for 30 seconds. Remove the chicken from the skillet.
Increase the heat to medium-high. Stir the stock, Italian seasoning and vinegar in skillet and cook for 3 minutes.
Return the chicken to the skillet. Reduce the heat to low. Cover and cook for 5 minutes or until the chicken is cooked through. Add the grapes. Serve with the pasta.