I adore pistachios. I love almonds. I like to add things I love to tart crusts. So I went from an almond to a pistachio pastry, and I liked it. Use salted pistachios for a undertone similar to the one you´d have by adding salted butter. Prebake the crust before pouring a filling, as it´s quite delicate and would be rather soft otherwise (which I personally like, but perhaps you don´t ) . As a topping, lemon, grapefruit or (blood) orange curd will work nicely here. And a meringue swirl, if you like it extra sweet and want to use up the three leftover whites. —Sabine
In a stand mixer fitted with the paddle attachment (or by hand), working at low to medium speed, mix all the ingredients except water until you obtain a fine crumble, 3-5 min. Then add water 1 tbsp at a time, until the dough comes together. At the end, there should be no more visible butter flakes.
Shape a ball, wrap in cling film and refrigerate for 1 hour or longer.
Line 6 well greased tartlet tins with the pastry, cover each one with a circle of parchment paper and good handful of oven proof weights (marbles, lentils, beans etc).
Prebake in a preheated oven (180°C/350°F) for a couple of minutes (7-10), until slightly golden.