Put the chicken in a bowl and toss with the oil, a quarter-teaspoon of salt and a generous grind of pepper.
Put a medium, heavy-based casserole for which you have a lid on a medium-high heat. Sear the chicken legs (in two batches, if need be) for five minutes, turning them once, until the skin is dark golden brown, then remove from the pan.
Put the carrot, onion, garlic, bay and thyme in the pan and cook for five minutes, stirring regularly, until softened. Return the chicken to the pot, add the stock, anchovies and a good grind of pepper, then cover, turn the heat to medium-low and leave to simmer gently for an hour.
Lift out the chicken from the pot, turn up the heat and boil for 10 minutes, until the liquid is reduced by a half and you have about 300ml left. Meanwhile, pull the meat off the chicken bones in large chunks; discard the bones and thyme stalks.
Bring a large pot of salted water to a boil, cook the pasta until al dente, then drain. Add the chicken meat and pasta to the reduced sauce and vegetables, mix well, then divide between four plates, layering the rocket between tongfuls of the pasta mix. Drizzle with oil and serve.