For the chile purée, we use boiled and blended jalapeños and serranos. For additional toppings, we love to add pico de gallo, jalapeños and sour cream! Cutting the American cheese into smaller pieces will make it cook faster. Make sure to stir the cheese frequently to prevent scorching. This can also be made in a slow cooker to be less hands-on, but it will significantly lengthen the cook time.