1/4 (or 1/2) a chicken, take the skin off, spicy rice and corn on the cob. Most SWers take the chicken as free, rice as 1.5 syns and the corn is free.
Its probably the best place out to eat as its all so simple! Chips are a no :-( but you can have the fat free frozen yog at about 3 syns. If you go to the SW board and find the Eating out forum there is loads on Nandos in more detail.
Enjoy, I totally love it and I'm off there tomorrow night!
Bx