Preheat oven to 200°C (180°C for fan assisted ovens) / Gas 5.
Cut the pastry into 8 equal portions, roll out to line each tart tin. Using a fork, gently prick the base of the pastry and add a sheet of greaseproof paper on top. Fill with baking beans and blind bake in the oven for 10 minutes. Remove the beans and paper, brush with the beaten egg and return to the oven and cook for another 5 minutes.
Meanwhile beat together the eggs, cream, milk and seasonings.
After 10 minutes, remove the tray from the oven and remove the baking beans and paper from the cases. Divide the asparagus spears and salmon pieces between the cases, gently pour over the egg mixture and return to the oven to bake for 15 -18 minutes or until the pastry is golden brown and the egg mixture has set.
If desired decorate with a couple more asparagus tips and zest of lemon.