Build the base. In a large skillet, melt butter over medium heat. Once hot, add onions. Season with salt and pepper. Cook until onions start to become translucent. Add corn and cook for a few more minutes. Add heavy cream and lower heat. Let simmer for 15 minutes. Turn off the heat and let cool. Add half of the mixture into a blender and blend until smooth. Marry the two mixtures back together.
Add the chicken and bake. Heat oven to 375° F. Shred the rotisserie chicken and place it into a bowl. Toss with BBQ sauce and add into a greased 2-quart baking dish. Pour the creamed corn over top of the BBQ chicken and top with fried onions. Bake for 30 minutes.