Preheat the oven to 180 degrees. Blanch the green beans in boiling water for 4 minutes, until just tender but still squeaky. Brush the cod with olive oil and season it liberally. Roast for 15 minutes. Meanwhile, heat the remaining olive oil in a deep frying pan, add the shallot and fry until transparent on a low heat. Add the garlic and ham and fry for a further few minutes. Throw in the green beans, artichoke hearts and parley and season, adding the sherry vinegar. This can be removed from the heat and served at room temperature as soon as the cod is done.