Crock Pot Sesame Honey Chicken

So earlier this week I made crock pot sesame honey chicken- another recipe I found from pinterest.  It is Advocare friendly, but had soy so it wasn't Eli friendly but may be okay for many others with allergies.  It is gluten free :)
In the crockpot, you put...
   2 lbs boneless skinless chicken breasts
   season with black pepper
In a bowl combine...
  1/3 cup low-sodium soy sauce (or tamari)
  1/4 cup honey
  1/4 cup tomato paste
  3 Tbsp rice wine vinegar
  2 cloves minced garlic
  1 Tbsp water
  1 tsp sesame oil
  1 tsp onion powder
  1 tsp sriracha hot chili sauce
Pour over chicken and cook on low for 3-4 hours.
Remove chicken and shred, sit aside.
In a small bowl combine...
   1/4 cup water
   1 heaping Tbsp cornstarch
Add to the crockpot and stir to combine, turn on high for another 15-20 minutes to slightly thicken.  Return the chicken and mix.
You can serve this over rice and garnish with sesame seed and chopped scallions.

It was good...but was missing something.  The recipe said you can add more sriracha to taste and I think we would have liked that.  It also might have been better with some onion and celery chopped in it.  It was good enough we may try  it again with some experimenting. 
There were some comments on this website about using frozen chicken and it will increase the cooking time...the only thing I worry about that is frozen chicken as it cooks gives off juices which may increase the amount of liquid in the pot.  It should be easy to make this on the stove too.