It was one of my lovely followers, Rotwein, who recently told me about a new pastéis de nata shop about to open in Covent Garden. When heading into Covent Garden yesterday afternoon to meet my friend Annie at Cinnamon Bazaar, I did a quick online check and it seemed Santa Nata hadn’t yet opened. But then, while wandering around the area for a short time before dinner, I just happened upon it in Russell Street, just off The Piazza.

In the window two bakers were rolling out long sheets of pastry and putting together the famous little Portuguese custard tarts.

The tarts were created by monks in the 18th century at a monastery in the parish of Santa Maria de Belém in Lisbon. At the time the monks and nuns used egg whites to starch their habits, which resulted in lots of leftover egg yolks! From these eggs yolks, the pastéis de nata was born. When the monastery closed in 1834 after the Liberal Revolution, the recipe was sold to a sugar refinery who opened Fábrica de Pastéis de Belém. This pastry shop still exists and in 2009 the Guardian, in its list of the 50 best things to eat in the world and where to eat them, named Belém’s pastéis de nata at No.15.

The new pastelaria in Covent Garden, Santa Nata, takes its name from the origins of the tart in Santa Maria. Owned by a Portuguese family, they’ve been baking since 1900 and own seven bakeries in Portugal. Their tarts are handmade daily by a Portuguese master pastry chef and his team and a bell is rung every time a fresh batch comes out of the oven.

So seriously is this little custard tart taken, that Santa Nata sells only the classic variety. Here there is only one tart to buy. Other places selling pastéis de nata have sprung up in London in recent years, and I’ve passed shops where different flavours are offered, but there’s no commercial messing about with the famous tarts at Santa Nata. Here is the real thing.

Of course I had to go inside. And once inside, I had to buy some. I chose a box of 4 for £8. You may only be able to eat the classic pastéis de nata here, there is no other food, but there are drinks on sale: a choice of coffees, tea and water. There is also port and ginjinha at £6 a glass. Ginjinha is a cherry liqueur that’s traditionally drunk with the tarts.

The shop is open 7 days a week from 10am to 8pm (closing at 10pm on Fridays and Saturdays). There’s nowhere to sit down; this is strictly takeaway.

I carried my little tarts carefully through the rest of the evening. Fortunately they were beautifully packed in a box and I was also given sachets of icing sugar and cinnamon to sprinkle over them – cinnamon is a traditional accompaniment.

As I ate supper early, I was home soon after 9pm. So really, how could I resist trying a pastéis de nata? And shouldn’t I eat one while it was still very fresh? Just to see what it was like and how good it was …

I had neither port nor ginjinha at home but made an espresso and – because it seemed fun to do so – served it in a little espresso cup that my daughter Nicola bought me in Lisbon years ago. And I of course sprinkled over some of the cinnamon.

Wow! It really was gorgeous; very special. The pastry was so light and crispy – as it should be – and the creamy custard nicely luxurious but not too sweet. I can see that every time I go to Covent Garden, I’ll have to go in and buy a box! Meanwhile, I have another for this evening and have given the remaining two to son and daughter-in-law. Pastéis de Nata are a great family favourite.