You can fill this tart with any jam or nut you like. There is nothing like a crispy fresh walnut though with a hint of Rose
Just a note. Add just enough liquid to bring the pastry together.
When baking blind make sure you bake the pastry till it is golden crisp and cooked through. That way the finished pastry will be gloriously crisp and perfect. It wont cook too much more once filled and baked again