Place the chicken breasts side by side in a shallow dish. Mix together the lemon juice, garlic, honey, balsamic vinegar, 1 tbsp olive oil & 1 tbsp chopped parsley and pour over the chicken. Turn the breasts over until well coated. Leave in the fridge to marinate for 30 minutes.
Brush a non stick griddle pan with the remaining oil and heat until very hot. Lift the chicken breasts from the dish (reserve the marinade) and add them to the pan.
Sear quickly for 1-2 minutes on each side until the chicken browns, lower the heat and cook for about 10 minutes or until the chicken is done, turning the breasts over once or twice.
Pour the reserved marinade over the chicken, remove from the pan and arrange on serving plates. Grate over the lemon zest and scatter with the rest of the parsley. Cut the lemon into wedges and serve with the chicken.