preheat oven to 410 degrees. in a small saucepan, combine the butter, sugar, water, and salt for the crust. heat over low heat for 10-12 minutes, or until butter is fully melted and beginning to brown at the edges.
remove from heat and add flour, mixing quickly until all are incorporated and dough ball is pulling away from sides and forming a ball. turn out into a 9 x 9 well-greased tart pan.
allow to cool slightly, then press into pan to form crust shape. puncture bottom with a fork to allow steam to escape. fill with either pie weights or beans and bake 13-15 minutes or until crust is beginning to golden. set aside.
in a medium bowl, combine goat cheese, cream cheese, honey, vanilla extract, and salt for filling. mix well and set aside. once pie crust is baked, fill with the prepared filling using a rubber spatula and bake another 5-8 minutes, until crust is fully baked and golden brown. allow to cool completely.
begin your curd. in a a double boiler or bain marie on a low simmer, whisk together the lemons, sugar, yolks, and salt. continue whisking for 6-8 minutes, until mixture is a rich golden and is thoroughly coating the back of a spoon.
remove from heat and add butter in chunks separately, whisking until each is completely melted.
cool in refrigerator for 20-30 minutes, until thickened, then pour over cooled tart.
top with blackberries and mint leaves.