Combine the yoghurt, lemon juice, garlic, mint, salt and pepper in a large bowl and mix well.
Cut boneless skinless chicken breast halves - cut into 4cm chunks depending on your wood skewers. Toss the chicken in the marinade and allow it to marinate at room temperature for 10 minutes. (If you want to marinate it for longer refrigerate the chicken.)
Grill or bbq the chicken, turning once, until golden on both sides and cooked through but still succulent, about 10 minutes total. Serve immediately, with lemon wedges, if you like.
Don't leave to cook unattended as the marinade may cause chicken to crisp rather quickly.