Marinate chicken overnight (minimum 3 hours).
Mix sauce
Cook chicken, rest 3 minutes, assemble gyros as follows: Sauce, chicken, lettuce, tomato, onion, chips, sauce. Fold, devour!
Mix the marinade ingredients in a large bowl. Add the chicken and mix well to coat. Marinate in the fridge for 24 hours (absolute minimum 3 hours!).
Mix the sauce ingredients in a bowl and set aside for at least 20 minutes to let the flavours meld.
Heat a large non stick pan over medium high heat. Cook the chicken in batches for 3 - 4 minutes on each side until deep golden and cooked through.
Remove chicken onto a tray. Loosely cover with foil and rest for 3 minutes, then slice into 1 cm / 0.4" pieces.
Heat the pita bread until warm and pliable.
Spread 3 tablespoons of the sauce down the middle. Pile the chicken onto the sauce, add lettuce and tomato on one side. Sprinkle with red onion, pile chips on top, drizzle with more sauce. Fold to enclose, wrap in foil to keep everything in place.
Serve gyros with extra sauce for dunking!
