1. For the filling, combine the cream and sugar in a pan and bring to the boil. Remove from the heat and leave to cool for 30 minutes.
2. Preheat the oven to 125C. Whisk the egg yolks in a bowl. Pour in the sweet cream and whisk to mix, then strain the custard into a jug.
3. Place the tart case, in its tin, on the pulled-out oven shelf. Fill with custard right to the top. Grate over the nutmeg.
4. Gently push the shelf back into the oven and bake for 25- 35 minutes until just set. Allow to cool once cooked.
5. For the prunes, combine prunes, sugar, cinnamon and zest and juice in a pan with 100ml water. Cover and bring to the boil, then simmer for 5 minutes. Remove from the heat and leave to cool, still covered.
6. To serve, remove the tart from the tin and cut into wedges. Serve with prunes and juice alongside each slice.

Cook's tip

This tart is better served at room temperature, about one or two hours after baking. Don’t serve straight from the oven – the resting time will make cutting it easier.