First and foremost make the pastry. Rub the butter into the flour until you have breadcrumbs and then add drops of water until it comes together. Chill in the fridge for 30 minutes or so. Roll the pastry out and divide into four pieces. Line each tart tin with the pastry and prick the base with a fork. I thought I’d make a right mess of lining the tins but it was really quick and simple; no holes and no patching up required.I tried that trick of pushing the rolling pin over the pastry when it’s in the case to remove the excess pastry from the edges and it worked brilliantly. Line the tarts with some baking paper and fill the tart cases with baking beans. Bake in a preheated oven at 200C for 15 minutes then remove the baking beans. I don’t think I was quite firm enough pushing my beans down as I did get a few air bubbles so I’ll be sure to be more forceful next time.
The fiddliest part was the unfortunate but necessary step of removing the skins from the chorizo. They may be natural skins and fine to eat but I’d had them before and ended up having to pull the skins off after cooking and out of my teeth. I wasn’t prepared to spend the evening flossing so skin removal was essential. Once the skins are removed, chop the chorizo and fry on a medium heat so the oil runs out of the chorizo and it gets nice and crispy. Remove the chorizo from the pan leaving some of the oil and put the onion in. Fry the onion until soft and going brown at the edges; the smell was divine.