Jersey Royal Potato and Caramelized Onion Tart with Balsamic Glaze

Preheat oven to 200°C (180°C fan/Gas Mark 6).

Roll out the shortcrust pastry on a lightly floured surface and line a 9-inch tart tin. Trim the edges and prick the base with a fork. Blind bake for 15 minutes using baking paper and baking beans or rice.

While the pastry is blind baking, prepare the caramelized onions. Heat the olive oil and butter in a large pan over medium heat. Add the sliced onions and cook gently for 20-25 minutes, stirring occasionally, until they are softened and golden brown. Season with salt and pepper.

Remove the baking beans and paper from the tart case. Spread the caramelized onions evenly over the base of the tart case.

Arrange the thinly sliced Jersey Royal potatoes in an overlapping pattern over the caramelized onions. Sprinkle with the fresh thyme leaves, salt and pepper.

Brush the pastry edge with beaten egg for a golden crust (optional).

Bake the tart for a further 20-25 minutes, or until the pastry is golden brown and the potatoes are tender.

Remove the tart from the oven and let it cool slightly before drizzling with balsamic glaze.

Serve warm or at room temperature.