Combine diced bell pepper, pineapple topping and can add BBQ sauce to your burger to your taste. Careful not to add too much so your burger doesn't fall apart on the grill. You may want to add an egg to help burgers hold their form. Form into patties and grill.
Top with Pepper Jack cheese. I find it is a great contrast to the sweet burger. Don't forget carmelized onions!
You can reserve some of the pineapple topping to use as a condiment like you would mayo. Have fun with it. Make your own combination.