Best-quality butter puff - whether homemade or store-bought - is
really the making of this tart.
300 gmbutter puff pastry (such as Carême)350 gm(about 5½ large stems) rhubarb, cut into 8cm lengths200 gmstrawberries, hulled and halved55 gm(¼ cup) raw sugarTo serve:Greek-style yoghurtFrangipane150 gmbutter, softened and diced110 gm(½ cup) caster sugar½ tspvanilla bean paste150 gmalmond mealCandied seeds80 gmpistachios1 tbsppepitas1 tspfennel seeds55 gm(¼ cup) white sugar
For candied seeds, stir ingredients in a saucepan and over medium-high heat until sugar begins to crystallise and cling to seeds (8-10 minutes). Spread onto a baking tray lined with baking paper and set aside to cool. Seeds can be stored in an airtight container for up to 1 month.
For frangipane, beat butter and sugar in an electric mixer until pale (3-5 minutes), add vanilla and almond meal, then beat on low speed until well combined (1-2 minutes). Refrigerate until required. Frangipane will keep for 3-4 days; use straight from fridge.
Preheat oven to 180C. Roll out pastry on a lightly floured surface to a 12cm x 35cm rectangle, then transfer to a baking tray lined with baking paper and dock all over with a fork. Spread a thin layer of frangipane over pastry, leaving a 2cm border. Arrange rhubarb crossways over the pastry, top with strawberries, scatter with sugar and bake until pastry is golden and fruit is tender (35-40 minutes). Scatter with candied seeds and serve warm or at room temperature with yoghurt alongside. Best eaten on day of making.