Marinade for Chicken Breasts

This is a great marinade for chicken.  The flavor is amazing!  
-2 Tbs balsamic vinegar
-2-3 tsp dried oregano
-1 1/2 Tbs Dijon mustard
-2 tsp garlic powder
-1/4 cup extra virgin olive oil
-salt and pepper, to taste
-4 boneless, skinless chicken breasts, cut in half
Combine all spices into large Ziploc bag.  Close bag and shake very well, until well mixed.  Add chicken to bag.  Close and shake again, making sure that each piece of chicken is well coated with marinade.  Refrigerate and let marinate for at least 6 hours.  Grill chicken and enjoy!