Mix flour with 1 tbsp. Sugar and a pinch of salt. Add cold butter and rub with your hands until bread crumbs.
Add 1 chicken egg to the flour mixture, knead a homogeneous plastic dough, gradually adding 1 tbsp of ice water. (maybe 1-2 tablespoons of water will be enough).
Knead the dough thoroughly, then roll into a ball, wrap in plastic wrap and refrigerate for at least 10-15 minutes.
Mix cottage cheese, sour cream, remaining sugar, starch, 2 eggs in a bowl. You can use potato starch instead of cornstarch. Armed with a submersible blender, grind the mixture until smooth without grains of cottage cheese.
Take out the chilled dough, roll it into a 4-5 mm thick circle, and place it in a baking dish. Form neat sides of the same height (3-5 cm, depending on the diameter of the mold).
Pour the curd filling into a mold with shortcrust pastry. If a one-piece pan is used for baking the tart, for easily getting the cake, you can make two strips of parchment paper slightly longer than the edges of the pan and lay them in a criss-cross shape. After baking, the tart will be easy to reach by pulling on the edges of the paper strips.
Cut the apricots in half, remove the seeds and carefully place the apricot halves on top of the curd filling. Send the cake to an oven preheated to 356 ° F (180 ° C) for 40-45 minutes. If the top of the tart begins to brown ahead of time, you can cover it with foil.
Serve the tart to the table and cut it after it has cooled do.