Chop each piece of chicken into 5 chunky pieces, leaving the skin on, and place in a bowl, along with the lemon juice and zest, oil, garlic, oregano, white wine vinegar and plenty of seasoning.
Cover and leave to marinate overnight or for a few hours . To cook the chicken, pre-heat the grill to its highest setting at least 10 minutes ahead, then first thread half a bay leaf on to the first skewer, followed by a quarter-slice of lemon, then a piece of chicken. Carry on alternating the lemon and chicken until you have used 5 pieces of chicken, finishing off with a lemon quarter and another bay leaf half at the end and making sure you pack everything together as tightly as possible.
Repeat with the second skewer, then place them both on a grill rack, and underneath the rack place a heatproof dish to catch the juices. The kebabs should be 4 inches (10 cm) from the grill, and as they cook you need to baste them with the marinade juices. They will need 10 minutes on each side to cook through and become nice and dark and toasted at the edges.
While they’re under the grill, mix the gremolata ingredients together and have it ready.When the chicken is done, transfer it to a serving plate and keep warm. Put the rest of the marinade, plus the basting juices, in a saucepan and boil to reduce to a syrupy consistency, which will take about 2 minutes.
Pour this over the chicken and sprinkle the gremolata all over to serve.