To make the parmesan shortcrust pastry, place flour, salt, butter and parmesan in a food processor. Process until mixture forms fine crumbs. Add egg yolk and water. Process until mixture just comes together. Shape dough into a disc. Cover with plastic wrap. Refrigerate for 30 minutes or until just firm.
Preheat oven to 200C/180C fan-forced. Grease a 2.5cm-deep, 11.5cm x 34cm (base) loose-based fluted tart pan.
Roll out pastry between 2 sheets of baking paper until 5mm thick. Line base and sides of pan with pastry. Trim edges. Place on a baking tray. Line pastry with baking paper. Fill with baking weights or uncooked rice. Blind-bake for 10 minutes. Remove weights and paper. Bake for a further 5 minutes. Cool completely. Reduce temperature to 180°C/160°C fan-forced.
Discard skin and bones from salmon. Flake into large pieces. Place in a bowl. Add dill, chives and lemon rind. Toss to combine. Spoon mixture into prepared pastry case. Whisk eggs, sour cream and parmesan in a bowl. Season with salt and pepper. Pour over salmon mixture.
Cut asparagus in half crossways. Arrange asparagus over top of filling. Bake for 30 to 35 minutes or until filling is just set. Stand for 15 minutes. Carefully remove from pan. Serve warm or cold.