Preheat the oven to 220ºC, fan 200ºC, gas 7.
On a lightly floured surface, roll out the pastry to a thickness of around 3mm. Line a 20cm greased round loose bottom tart tin with the pastry. Place a circle of greaseproof pastry on top followed by baking beans. Chill for 10 minutes.
Bake in the oven for 15 minutes then remove the paper and baking beans. Make an egg wash by beating one of the eggs with a little water. Brush it over the pastry and turn the oven down to 180ºC, fan 160ºC, gas 4.
In a mixing bowl, combine the remaining 6 eggs and cream together. Season with salt and pepper and set aside.
Sprinkle the cheese, tarragon, spring onion and crab over the tart base. Slowly pour the egg over the cheese, crab meat and herbs.
Return the pie to the oven and bake for 25 minutes until the custard is set and the pastry is golden. Leave the tart to cool before slicing to serve.
Recipe courtesy of Great British Chefs and Nathan Outlaw.