Combine the sliced lemon grass, shallots, turmeric, sugar and oil in small food processor and blend to make a fine paste.
Cut chicken breast into 2cm X 8cm strips and pour marinade over.
Mix well, cover and refrigerate for 1-2 hours. Cut cucumber into long strips 1 cm thick and 8 – 1cm long. Set aside.
Heat 1 tablespoon oil on non-stick frying pan and cook half the chicken strips for 3 – 4 minutes per side – till slightly charred around the edges but centre is still juicy. Remove and cool on a plate. Heat remaining tablespoon of oil and cook remaining pieces likewise. To make Mission tortilla wraps pliable, place each wrap on a well-heated frying pan for 10 seconds. Turn and heat other side for another 10 seconds.
Lay 1 – 2 lettuce leaves on a tortilla wrap and place chicken and cucumber strips in the centre. Roll up tightly. Cut each roll into neat 3 cm slices and secure each piece with a toothpick.