Ingredients
Makes 2 tarts, each serves 4
300g (2 cups) plain flour, preferably organic (available from supermarkets and health food stores)
2 teaspoons Maldon sea salt
160g cold butter, finely chopped
1 egg, lightly beaten
2 tablespoons pouring cream
Filling
50g salted butter
5 large leeks, trimmed and cut into 2cm-thick slices
1 bunch of thyme, leaves removed from half the stalks
150g Heidi Gruyére, grated
Method
Combine flour and salt in a large bowl, add butter and toss to coat with flour, then, using fingertips, gently rub butter into flour so that only small chunks remain. Add ½ cup iced water and, using a flat-bladed knife, stir until mixture almost comes together. Using your hands, gently bring dough together, divide in half, then wrap in plastic wrap and refrigerate for 20 minutes.
For filling, melt butter in a large saucepan, add leeks, thyme leaves and ¼ cup water and simmer, stirring occasionally, over low heat for 30 minutes or until leeks are soft, mixture is thick and water has evaporated. Season to taste with sea salt and freshly ground black pepper.
Roll out one piece of dough on a lightly floured surface to form a 23cm rounde then carefully transfer to an oven tray. Spread half the leek mixture over pastry, leaving a 2cm border, then fold uncovered border over leek mixture, pleating to fit and leaving centre uncovered. Sprinkle tart with half the cheese and brush pastry edge with half the combined egg and cream. Repeat with remaining pastry, filling and cream mixture.
Bake tarts at 180C for 20 minutes or until pastry is crisp and golden. Cool on trays for 10 minutese then serve warm or room temperaturee cut into wedges, sprinkled with remaining sprigs of thyme. Tarts are best eaten on day of making.