Gagomes,
Just rub the 'nest like' leaves between your palms to grind it to a powder like substance. Don't worry too much about getting it to a fine powder.
There is an alternative cooking method that doesn't require skewers and provides a nice addition which cooks in the oven as opposed under the grill. Preheat your oven to it's hottest setting, slice an onion and separate the rings, place on a baking tray and place the chicken on the onion. Pop it in the oven for about 15-20 mins or until cooked. Done right you should end up with succulent chicken with singed edges and tobacco onions to accompany it.