Oven on at 180 Fan. Butter and then flour deep fill foil tart cases. Shake out any excess flour and put to one side.
Roll out the puff pastry to the thickness of a £1 coin, cut out 12 – 14 circles to line the cases with a little bit overlapping the top once you’ve gently pushed snugly into the sides and bottom. Pop them on a baking sheet and into the oven for 20 -25 minutes until they are golden brown and crispy. Take them out and leave to cool. Lower the oven temperature to 150 Fan.
While they are cooling make the custard. Heat the milk, sugar and vanilla seeds in a medium to large saucepan over a medium heat stirring every now and again until bubbles form around the edges of the pan, then you take it off the heat.
Put the cornflour into a large bowl, add a splash of evaporated milk and whisk together to make a smooth paste. Pour in the rest of the evaporated milk and keep whisking until it is fully incorporated. Add the eggs and yolks to the bowl and beat together well. Add the hot milk mix gradually continuing to whisk. Return the whole lot to the pan and onto a gentle heat, keep stirring until thickened enough to coat the back of a wooden spoon. Sieve the mix into a jug to get rid of any lumps.
When the tart cases are cold trim off the excess pastry from the edges. Gently hollow out the tart cases, removing a little of the pastry to make more room for the filling. Carefully pour in the custard, almost to the top and then add the grated nutmeg, generously! Bake for 10 – 15 minutes in the oven until they set but still wobble… allow to cool and then enjoy.