Preheat your oven to 450.
Mix together:
1/2 cup of dijon mustard
1/4 cup of maple syrup
1 tablespoon of rice wine vinegar
1 onion, sliced
3 dashes frank's hot sauce
2 dashes red pepper flakes
5 chicken breasts, boneless and skinless
Mix together the above ingredients in a bowl until well blended. Place chicken into a sprayed 9x13 pan. Salt and pepper the top of the chicken. Pour sauce over each chicken, so it's all coated. Place sliced onion evenly over the top, separated into rings. Bake for 45-50 min. Let sit for 5 min then serve with sauce over top.
I served mine with wild rice pilaf. It was good :)