Marinade the chicken fillets in the lemon juice and olive oil whilst you make the guacamole. Place the tomatoes in a basin and pour over boiling water to cover. Leave for two minutes. Make a small incision in the base of the tomatoes and slip the skins off. Scoop out and discard the seeds and finely chop the flesh.
Halve and stone the avocados, then scoop out and mash the flesh with the lemon juice. Add the chopped tomatoes, spring onions, chilli, Tabasco and seasoning. Taste at this stage and add another drop or two of Tabasco if you like it hotter.
Heat a griddle or frying pan, pour in the olive oil and cook the chicken fillets for 3-4 minutes per side until golden brown. Check that it is cooked through with no pink showing. Warm the pitta breads in either the toaster or a medium oven, split open and fill with guacamole and the chicken fillets.
For top tips on protecting you and your family when preparing raw meat and poultry, visit Food Safety in the Home and view the full Food safety at home video.