Peel the shallots and garlic, then trim the green beans.
Drizzle the chicken with oil and rub in a generous amount of sea salt and black pepper.
Place the chicken in a casserole dish and surround with the shallots, garlic, leeks, fennel and bay.
If you’ve got thin-skinned lemons, remove the pips, squeeze in the juice, then add the lemon halves too. Otherwise, peel the zest off in thick strips and add with the juice, discarding the halves.
Add the wine and 400ml water, and bring to a boil over a high heat. Reduce the heat to a simmer and cover. Simmer gently for about 1¼ hours, till the chicken is cooked and tender. Spoon over the broth now and then and check it’s not bubbling too vigorously.
When it’s 10 minutes from being done, check the liquid for seasoning. Add the green beans, then put the lid back on and leave to finish before removing from the heat.
Pick all the herb leaves, discarding the stalks, then place in a food processor. If you can fish out the garlic from the casserole, add that too. Blitz to a paste, then transfer to a small bowl. Stir in a little oil and a few spoonfuls of braising liquid.
Sit the chicken on a board (discard the skin) and carve into thick slices. Divide the meat between bowls with the vegetables, spoon over some braising liquid and serve with the dressing.