Easy Balsamic Chicken

boneless (skinless chicken breasts,rinsed and sliced in half)

⁄2 teaspoon salt

⁄2 teaspoon pepper

olive oil

small onion (chopped)

garlic cloves (chopped)

⁄4 cup balsamic vinegar

⁄2 teaspoon brown sugar

⁄4 cup low-sodium chicken broth

dried rosemary

dried basil

dried oregano