Preheat oven to 220°C. Mark six 8cm rounds on a sheet of baking paper. Place sheet, marked side down, on a flat baking tray. Heat oil in a non-stick frying pan over medium heat. Add leek and cook, stirring, for 3 minutes or until soft. Transfer to a bowl and set aside to cool.

Using an 8cm round biscuit cutter, cut 3 rounds out of each pastry sheet. Using a warm knife (this makes it easier to slice cheese), cut cheese into 6 even rounds. Place a piece of cheese into the centre of each marked round on baking paper. Top with leek mixture and salmon. Top each salmon mound with a pastry round. Press pastry edges down to cover and seal in filling. Spray pastry with oil.

Bake tartlets for 15 to 18 minutes or until pastry is golden and puffed. Slide a palette knife under each tart and turn over. Place tartlets, cheese side up, on serving plates. Top with creme fraiche and dill. Season with pepper. Serve with lemon wedges.