01 -
In a food processor, combine flour, sugar, and salt. Add cold butter and pulse for about 1 minute until the mixture resembles pea-sized crumbs. Add ice water gradually, 1 tablespoon at a time, pulsing just until the dough begins to come together. Turn dough onto a floured surface and pat gently into a disk. Wrap in plastic and chill for at least 1 hour.
02 -
Combine rhubarb, strawberries, light brown sugar, lemon juice, lemon zest, corn starch, and vanilla seeds in a bowl. Toss until the mixture is evenly coated.
03 -
On a lightly floured surface, roll out the chilled dough into a large circle. Transfer dough to a parchment-lined baking sheet. Sprinkle the surface evenly with instant oats.
04 -
Mound the fruit filling in the centre of the dough, leaving a 4 cm border. Fold the dough edges over the filling, overlapping where necessary and pleating gently. Place the baking sheet in the freezer for 15 minutes to firm.
05 -
Preheat the oven to 190°C.
06 -
Remove galette from freezer. Brush the dough with beaten egg and milk mixture. Sprinkle generously with coarse sugar. Bake for 40–45 minutes, until the crust is deeply golden and the filling is bubbling.
07 -
Cool slightly and serve warm, accompanied by vanilla ice cream if desired.