Collect together your equipment (see Recipe Notes below) and ingredients.

First make the puff pastry – if you are making your own pastry, you need to make this first. You should start making it 5 – 5½ hours before you want to make the tarts.

Preheat oven to Fan Oven 290°C /310°C/550°F/Gas 10 or as hot as your oven will heat.

Secondly, make the custard, starting time time for it to cool down – heat the sugar, water, lemon peel and cinnamon over a moderate heat until the sugar has dissolved, and it reaches 106°C/223°F. It will turn into a thick syrup.

Strain the syrup.

Meanwhile, in a heatproof jug, mix the flour with 95ml milk to make a paste.

Bring the remaining milk to a simmer and, when steaming, pour over the milk and flour paste and mix thoroughly with a balloon whisk.

Wash the saucepan thoroughly – this is an important step. If you do not do this, your custard may stick to the base of the pan and burn.

Pour the milk and flour back into the clean saucepan. Heat over a moderate temperature and cook, stirring for 3 minutes, until thickened.

Slowly add the syrup to the flour and milk, whisking all the time.

In a large bowl, beat the eggs – slowly add the custard, beating as you pour it in with a balloon whisk.

As soon as it is all incorporated, add the butter and beat until it is incorporated.

Strain the custard into a jug or bowl.

Cover with cling film and set on one side.

Line the Pastéis de Nata or muffin tins with pastry: on a lightly floured work surface and with the short side of the pastry in front of you, roll out the pastry roughly 35cm/14in – 40cms/16in long and 10cms/4in wide.

Brush off excess flour.

Start rolling the long side of the pastry, brushing off extra flour, with each small roll, until it is completely rolled.

Trim the ends from each end of the pastry.

Slice the pastry into rounds. If you are using Pastéis de Nata tins (as shown) each round of pastry should weigh 20g. If using a muffin tin, you will need 28g of pastry per muffin size tart. You will make between 10 – 15 tarts depending on the tin size. Place a pastry round into a greased tin.

Use your thumb and press the centre of the pastry. Continue pressing the pastry encouraging it to come up the sides of the tin. It needs to extend a little higher than the tin.

Now use your thumb to press down on top of the pastry so it comes to the same level as the tin and create a slightly thicker pastry crust at the top, around the edge.

Place the tins on a baking tray.

Fill the tins and bake the tarts: pour custard into the pasty cases, to just below the thickened area of pastry. They should be around four fifths full.

Bake at the top of a pre-heated very hot oven for 8 – 9 minutes until the custard has risen and is in a dome shape. The custard should be set but still be wobbly – it will continue to cook when you take it out of the oven – and the top of the tarts should be dark and caramelised. As the custards cool, the dome shape will settle and flatten.