Cut the butter into small dice. Place in a bowl with the flour and rub together until the mixture resembles breadcrumbs. Make a well in the centre and add the water and a pinch of salt. Bring the mixture together to form a dough. Take care not to overwork the mixture at this point. Roll the dough into a ball, flatten into a disc and then chill in the fridge for half an hour.
Preheat the oven to 180'c.
Roll the pastry out and press into a lined tart case, leaving a little pastry hanging over the edge. Line with baking parchment and add baking beans. Transfer to the oven and blind bake for 12 to 15 minutes. Remove the baking beans and parchment, return the pastry to the oven and cook for 5 more minutes. The whole tart case should evenly cooked and a light golden colour. Use a sharp knife to neatly trim the edges of the pastry. Reduce the heat of the oven to 140'C.
Trim the end of the asparagus and peel the stalks. Cut into finger lengths and blanch in salted boiling water for 3 minutes. They should be bright green and just tender. Drain and refresh in a bowl of iced water and then drain again.
Beat together the egges and the crème fraiche. Season with salt and pepper and then stir in 3/4 of the grated gruyère. Cut the ham and the artichoke hearts into small pieces and scatter evenly in the base of the tart case. Arrange the asparagus on top and then add the crème fraiche filling to just below the rim of the pastry case. Sprinkle the remaining cheese on top and bake in the bottom of the oven for 30 to 35 minutes or until the filling is set and golden on top. Allow to cool and then serve with a fresh green salad.
«When baking with crème fraiche, be sure to cook at a low temperature to avoid it splitting.»