¼ cup cold buttermilk, plus a few tablespoons extra if required
FOR THE FILLING
4 medium kipfler potatoes
1 red onion, peeled and finely sliced
1 tablespoon butter
100 grams ham, roughly chopped
125 grams raclette cheese, grated
2 sprigs thyme
1½ cups cream
3 eggs
Method
To make the pastry, place the flour, sugar and salt in a bowl and whisk to combine. Chop or grate the cold butter into small pieces. Add to the flour and rub in with your fingertips until the mixture resembles damp sand and the butter is evenly distributed. Make a well in the centre and pour in the 1/4 cup buttermilk, stirring with a fork to combine. Once it comes together in a shaggy dough, knead together, and form into a disc. Wrap with clingfilm and refrigerate for one hour (or up to overnight).
Roll the rested pastry out into a large circle, approximately 5 millimetres thick. Line a 24cm loose-bottomed flan tin with the pastry and trim the edges. Refrigerate for a further 30 minutes.
Preheat the oven to 200C.
Line the pastry case with foil and fill with baking beans or dried pulses. Bake for 15 minutes, then remove the foil and baking beans and bake for a further 10 minutes. Set aside while you make the filling.
To make the filling, peel the potatoes and cut into 1-cm slices. Cook in boiling salted water for 5-10 minutes, or until just tender when poked with a skewer. Drain and set aside.
Melt the butter in a non-stick frying pan. Add the onion slices and cook on a low heat until completely soft and dark brown. Season with salt and pepper and set aside.
Turn the oven down to 180C.
Place the onions, potato slices, ham, and grated cheese into the pastry case. Sprinkle the thyme leaves over.
Whisk together the cream and eggs and season with salt and pepper. Pour into the flan tin. Bake for 25-35 minutes or until golden brown and just set.
Allow to cool slightly for the filling to set before slicing.
