Combine the tuna, pepper, carrot, cucumber, sweetcorn and shredded round lettuce in a large mixing bowl. Mix well using a fork until the ingredients are just combined then add the mayonnaise, yogurt and some seasoning and mix again until combined.
Spoon into the tortillas and roll up into cylinders. Cut in half and secure each half with a toothpick. Dress the plates with the spinach leaves and a few baby capers then sit the tortilla halves on top.