Weigh the flour, cold butter, salt, and turmeric into a mixing bowl.

Rub the cold butter into the flour mixture until it resembles coarse crumbs.

Add the 125 ml ice water and mix just until a uniform dough forms.

Shape the dough into a flat disc and wrap it tightly in plastic wrap.

Chill the wrapped dough in the refrigerator for 60 minutes.

Peel and cut the Delica pumpkin and potatoes into small even cubes.

Heat the olive oil with garlic and rosemary in a pan over medium heat.

Add the pumpkin and potatoes, then season lightly with salt.

Pour in the 250 ml water and cover the pan.

Cook until the pumpkin is creamy and the potatoes are tender, about 20 minutes.

Remove the filling from the heat and let it cool until warm.

Stir the Parmigiano Reggiano and Gorgonzola cheese into the cooled vegetable filling.

Preheat the oven to 170°C.

Roll out about two-thirds of the chilled dough to a 3 mm thickness.

Line the tart ring with the rolled dough, pressing it into the base and sides.

Spoon the pumpkin, potato, and cheese filling evenly into the pastry shell.

Roll out the remaining dough and place it over the filling.

Seal the pastry edges and decorate the top with leftover dough if desired.

Bake at 170°C until golden and set, about 40 minutes.

Rest the savory pie for 10 minutes before slicing and serving.