Place tomatoes, Edgell Corn Kernels and spice mix in a saucepan. Stir over medium heat until it comes to the boil.
Stir though John West Tuna and coriander into tomato mixture and gently warm through.
Place lettuce on tortillas, top with tuna mixture, guacamole and drizzle with sour cream. Serve immediately with lime wedges and garnish with coriander.