Make the blueberry curd from this recipe. It can be made a day or up to two weeks ahead of time.

Line an 8x8” or 9x9” square pan with parchment paper (two sheets so you have an overhang which you can use as a sling to lift it from). Preheat the oven to 350 F.

In a food processor, add the dry ingredients and pulse just to mix it all. Add the butter and pulse until it comes together in a rough ball. Press the dough into the bottom of the pan into an even layer - take your time packing it in and smoothing it down.

Bake the shortbread for 25-30 minutes until it’s nicely browned on the edges.

Whisk the tapioca or cornstarch into the blueberry curd until it’s well mixed. Pour over the cooked shortbread (while it’s hot) and tilt the pan to get it into an even layer. Bake for 15-20 minutes, until the edges are set and only the center jiggles.

Chill in the fridge for a few hours before serving. Slice with a hot, dry knife for clean cuts.