Tuna or any cooked chicken or meat can be added if desired. Simply add to the cheese mixture. You can also use jalapenos instead of regular chillies.
Please clarify on amount of cheese for ONE? Instinctively, I knew that 400g cheddar is a HUGE amount for 1 person but I always follow recipes to the letter on my first attempt. As expected, cheese was far too much to fit between 2 tortillas. Flavour of tortillas and filling was nice BUT way too much. - 22 Aug 2014