Preheat the oven to 200ºC/400ºF/gas 6. Halve any larger new potatoes. Trim the fennel, pick and reserve any leafy tops, finely slice the stalky part, then halve the bulb and cut into 1cm slices. Put it all into a 30cm x 35cm roasting tray, halve the artichokes and add with 2 tablespoons of oil from their jar, as well as a really good pinch of black pepper, then toss it all together. Pour in 300ml of water, cover the tray tightly with tin foil, and bake for 1 hour.
In a bowl, finely grate half the Parmesan into the cream and loosen with a splash of water. When the time’s up, remove the tray from the oven, discard the foil, spoon over the cream mixture and finely grate over the remaining Parmesan. Bake for a final 20 minutes, or until golden and cooked through, then sprinkle over any reserved fennel tops before serving.