In a food processor place the flour, sugar, salt and butter, process for a few minutes then add the white vinegar and the water. Process the ingredients until you get a dough. Wrap the dough in a plastic wrap and refrigerate it for at least 1 hour.
5.6 oz 1 ¼ cup all purpose flour, 1 tbsp sugar, ½ tsp kosher salt, ½ cup cold unsalted butter, 1 tbsp white vinegar, 1 tbsp water
Roll the dough using a rolling pin and cut circles using the top part of a glass. Place the circles into a previously greased muffin mold and bake for 20 minutes at 400°F (200°C).
Cut the squash into cubes, place it in a baking sheet prepared with baking paper at the same temperature for 20 to 30 minutes until it gets soft.
1 cup butternut squash
Chop the parsley and place it in a big bowl together with the previously prepared squash and crumbled feta cheese. Add the olive oil inside and stir with a spoon. Fill the previously baked cups with 1-2 tbsp of the filling.