Crock Pot BBQ Chicken

This recipe comes from my friend Mindy; you can use pork if you like that better. It's delicious and easy.

3 -3 1/2 lbs boneless, skinless chicken thighs (don't be tempted to use chicken breast- I've tried it and it's dry and tasteless)
1/2 cup brown sugar
2 T chili powder
2 t Worcestershire sauce
1 large yellow onion, chopped
1 can tomato paste
1/4 c cider vinegar
2 t salt
1 t dry mustard
optional: crushed red pepper or some other hot sauce if you like it spicy

Mix everything but the chicken in a crock pot; add the chicken thighs and stir to coat. Cook on low for about 6 to 8 hours. Shred chicken with a fork and serve on a bun with coleslaw.