Place flour on a surface and create a well in the centre.
Work butter and salt into the well using your fingertips.
Slowly mix in 125ml iced water until dough is grainy and marbled.
Form dough into a ball, wrap, and refrigerate for 20 minutes.
Roll pastry into a 40x20cm rectangle on a floured surface.
Fold the top and bottom thirds into the centre and turn 90 degrees.
Repeat the rolling and folding process, then refrigerate for 30 minutes.
Give the pastry two more turns and refrigerate for another 30 minutes.
Preheat the oven to 200°C.
Remove scallops from shells, cleaning and saving both shell halves.
Pat scallops and shells dry, then horizontal slice scallops in half.
Sauté vegetables and star anise in butter until softened.
Simmer with wine and fish stock, reducing liquid by half each time.
Stir in cream and reduce the sauce by one third.
Stir in tomato and herbs, then season to taste.
Roll pastry 3mm thick and cut into long thin strips.
Fill shell bottoms with sauce and scallops, then top with more sauce.
Seal shells together with egg wash and pastry strips.
Place shells on salt piles on a tray and bake for 12-15 minutes.
Serve the baked shells on fresh piles of salt.