- In a large bowl, combine onions, jalapeños, garlic, thyme, brown sugar, soy sauce, vinegar, olive oil, Teriyaki sauce, cayenne pepper, salt and pepper. Mix well and add to a large resealable Ziploc bag.
- Add the chicken breasts to the bag and refrigerate for a minimum of 4 hours (but preferably overnight).
- Cook on a grill over medium heat until centers are no longer pink, approximately 5 minutes on each side. Meanwhile, return juices to a medium saucepan and bring to a boil. Cook, stirring for 10-15 minutes and serve over top of the cooked chicken.