In a medium heavy-bottomed pan, add the sugar, lemon juice, lemon zest, 8 egg yolks, and butter and cook over medium-low heat. Stir constantly until the curd starts to gently bubble and begin to thicken. The curd is done when it easily coats the back of a spoon. Don't aim for too thick while it's cooking, as it will thicken up as it cools in the fridge. Once done, pour out into a bowl and cover with plastic wrap, pushing the plastic down onto the surface of the curd, this helps prevent it from forming a skin in the fridge. Refrigerate until the crusts are done and the tarts are ready to be assembled.
preheat the oven to 350°F. If you made the tart crust ahead of time and refrigerated it, allow it to rest at room temp for ~15 minutes before attempting to roll out. Lightly grease your tartlet pans and set aside. Gently roll out the crust onto a lightly floured surface, until the crust is ~1/4" thick. Cut the crust into oversized circles and gently drop into the tartlet pans, press into the sides, and trim the edges. If it crumbles or breaks in places, that's ok, just use a little piece of cutoff to repair it. If necessary, collect scraps and re-roll out to fill all the tartlet pans.
Place the 6 tartlets onto a baking sheet, and lay small sheets of parchment paper over each tartlet crust, and fill with pie weights or dry rice and bake for ~15 minutes, or until the crust has set. Remove the parchment and weights and continue baking for another 10-15 minutes or until the crust is a light golden brown and crisp. Once done, remove from the oven and allow to cool for a few minutes in the pan before moving to a wire rack to cool completely.
For the next step, I recommend keeping the tartlets in their pans until they're filled, as it can be easy to damage or crumble the crust while handling the tarts. Once the crusts are completely cool, evenly divide the lemon curd across the 6 tartlets, using the back of a spoon or offset spatula to spread it to the edges of the tart. There will be some lemon curd leftover, so don't feel like you need to use all of it, just make sure the tartlets are sufficiently filled (put the extra curd in a jar and refrigerate for later!) Place blueberries across the top in concentric circles, and when ready to serve, dust with powdered sugar and garnish with mint.
Enjoy!
