Preparation 1. Remove the packets of giblets from the body cavities of the chickens and set aside for another use. Remove and discard the fat just inside the body and neck cavities of the chickens. Rinse the chickens inside and out, under cold running water and then drain and blot dry inside and out with paper towels. Spatchcock the chickens - remove the backbone and skin with large poultry shears, while keeping the skin intact over the breast bone in front.Tease out the sternum. Slit the skin by the thighs, and draw the thighs inside the skin, so you have a flat chicken. Prepare the pesto. Place the dill, basil, garlic, walnuts, cheese and lemon zest in a food processor until very finely chopped. Adjust salt and pepper. With the machine running aid the oil, lemon juice and 3/4 cup of water. Set 1/2 cup of mixture asidePour the remaining pesto over the chicken spreading it on on the meat on bouth sides. Refrigerate covered for as little as two hours or overnight. 3. Grill about 12 to 15 minutes per side turning and applying the remaining pesto over them. Heat to 180 F. 4. Transfer the chickens to a platter with garnich from dill sprigs and lemon wedges to serve.