Preheat the oven to 180°C.
Stuff the bird cavity with lemon, crushed garlic, rosemary, and thyme then secure with string.
Butter the skin and roast in a tin for 35 minutes until the juices run clear.
Rest the bird upside down for 25 minutes and save the roasting juices.
Blanch the greens, mint, and parsley in boiling salted water then refresh in iced water.
Chop the greens and herbs with garlic, chilli, anchovies, and capers.
Mix the chopped ingredients with shallot, salt, cayenne, lemon zest, and olive oil.
Carve the bird and serve topped with roasting juices and the salsa.