To make the Tomato Salsa: Palace the tomatoes and cucumber in a bowl and toss with the rest of the ingredients. Taste for seasoning
To make the Chunky Guacamole: Then in another bowl mix the avocados, lime juice, scallions, chilli, garlic and yoghurt. Using a fork roughly mash everything together, season.
Heat the taco shells as per the packet instructions.
Bring everything to the table and let everyone help themselves.