8 largeslices cheddar or pepper jack cheese (8 oz)
Heat a large nonstick skillet to medium-low heat. Add olive oil and onions. Cook, stirring occasionally, for 45 minutes to 1 hour or until very soft and brown.
Preheat oven to 375° F. Coat the bottom of a 9x13 baking dish with cooking spray.
Break rolls in half so that there are two sections of 12 rolls. While keeping rolls connected, slice each section in half horizontally using a large serrated knife. Place bottoms of rolls in prepared dish.
Place chicken in a bowl then add 2 tablespoons of BBQ seasoning. Toss to combine. Spread evenly over rolls in the pan. Drizzle 1/2 cup BBQ sauce over the chicken. Add caramelized onions evenly across the top. Add cheese slices then place tops of rolls on.
Add 1 teaspoon BBQ seasoning to the melted butter and stir. Brush tops of rolls with butter mixture. Cover with foil and place in oven for 10 minutes. Remove foil. Bake 5-10 more minutes until golden brown. Serve immediately.
If onions start to get dry, add about 1 tablespoon of water to the pan.
Optional: Add a teaspoon of sugar to the onions to speed up the process.