Apparently I shouldn't just post a link to where I've written up the story about this tart, so here's the whole deal with even more apologies!
We (OK, OK, my wife) picked a sack of blackberries when we went for a walk along the old railway line the other day, and she's been hassling me to do something with them ever since.
Like, she said, make a tart. With crème patissiere. And pâte sablé.
Well, me and pastry - as they say in French - that makes two; I can't, won't make it. I buy it. And pre-made chilled pastry here is nicer than anything I can make myself, so good that people believe me when I say I made it myself. So I bought a 30cm round of ready-made pastry and blind-baked it, 25 minutes at 180°C turning it two or three times to ensure even cooking. Don't forget to repeatedly stab the base with a fork to stop it rising. And don't forget to put in your baking beans like I did - this forgetfulness leads to the sides sagging down.
While this is cooking, make the crème patissière: for a tart this size, use 500ml of milk, 100g of sugar, 5 egg yolks, 70g plain flour, a vanilla pod and a pinch of salt.
Put the milk on to heat with the split/scraped vanilla pod (put the whole pod into the milk to infuse - lots of the vanilla flavour comes from the pod itself rather than the seeds). Whisk together the sugar and egg yolks to the ribbon stage (lift up your whisk and trail the dribbles across the surface of the mix - it should stay in place looking a bit like a ribbon for a second or two). Then whisk in the flour thoroughly.
When the milk boils, pour a little into your flour/sugar/egg mix to make it liquid, then add the rest stirring all the time. When it's thoroughly mixed, pour it back into the saucepan and gently bring it to the boil. Stirring ALL the time, or it will go lumpy. Bring it back to the boil and simmer it for a couple of minutes to thoroughly cook the flour, then decant it into a clean bowl, whisking all the time to avoid those lumps.
When it's cooled a little, cover the surface with a layer of clingfilm (may be called Saran wrap in your part of the world) and refrigerate it. The plastic film stops a skin forming on top. At catering school we learned to dab a little butter onto the surface to stop the skin forming; my restaurant chef, after looking at me like I was a Martian when I suggested doing this, showed me the clingfilm method.
When everything has cooled down, check your crème for lumps. Whether there are any or not I like to whisk my crème patissière with an electric whisk at this point to make it easier to handle - a couple of minutes with the electric mixer and it'll pour easily into your pastry case, allowing you to smooth the surface nice and flat.
Then put the blackberries on top. In this example I've used the artisanal 'higgledy-piggledy' method, i.e. I just poured them on top, roughly smoothed them into a more or less even layer and then tucked in. If you have time and patience you can make them look more artistic, like this one I made earlier (three years earlier, in fact, that's how often the mood takes me to take the time to do it properly).
One last note: for various reasons (OK, I'm lazy and it was the first packet that came to hand) I used brown, less-refined sugar to make this crème patissière and it turned out very well, a subtly caramelised taste which is very pleasant.
