Preheat the oven to 200C/400F/Gas 6.
On a lightly floured surface, roll out the pastry and use to line a 25cm/10in loose-bottomed tart tin. Cover and place in the fridge for 15 minutes.
Line the pastry tart case with greaseproof paper and fill with baking beans.
Bake in the oven for 10-15 minutes.
Remove the greaseproof paper and beans and return the tart case to the oven for a further 3-5 minutes until it is just cooked.
Reduce the heat to 180C/350F/Gas 4.
In a small food processor, blend the ginger with the parsley and two tablespoons of sunflower oil.
Spread over the base of the tart case.
Scatter the crabmeat over the top of the ginger mixture.
In a bowl combine the eggs and egg yolks with the crème fraîche and season with salt and freshly ground black pepper.
Pour into the tart case.
Return the tart to the oven for 30-35 minutes or until just set.
Meanwhile, make the dressing. In a small bowl, whisk together the onions, lime juice, chilli, soy sauce, sunflower oil and sugar with one tablespoon of water. Season to taste.
Serve the tart warm with a drizzling of chilli dressing.