Mix all the butter ingredients together and blend well to form a soft paste.
Gently push your fingers under the skin of the chicken to pull it away from the flesh, do this all over the bird. Stuff pieces of spicy butter under the skin, massaging it into the chicken and smoothing out the lumps. Stuff the rest of the butter in the cavity.
Slice the lemons in half, and place one half in the cavity of the chicken and the others in the pan. Place the chicken in a high sided pan with the fresh herbs, stock and verjuice. Roast for 1.5 - 2 hours (depending on the size of your chicken) until golden brown and cooked through. If you find that the chicken ins browning too much during the cooking, loosely cover it with foil.