In a large deep skillet, melt the butter. Add the onions and cook until translucent.

In a separate bowl, whisk together the pineapple juice, brown sugar, garlic, ketchup, soy sauce, Worcestershire sauce, salt, pepper, onion powder, and ginger.

To the skillet, add the flour and stir it in until it appears pasty.

Add the pineapple juice mixture to the skillet and stir. Allow it to come to a simmer while stirring and cook for 5 minutes until it starts to thicken.

Place the chicken in a 3-4 quart crock pot. Pour the sauce over the top. Cover and cook on low for 6-8 hours.

Remove the chicken from the crock pot and shred with two forks. Add it back to the crock pot and cook for another 30 minutes.

To make the coleslaw, stir together the mayonnaise, vinegar, sugar, ground mustard, onion powder, salt, and pepper. Pour it over the coleslaw mix and stir to combine.

Serve the chicken topped with coleslaw on rolls.