Wash and cut the new potatoes into thin slices. Slice the shallots into thin rings.

In a small frying pan, heat olive oil over medium heat. Add the sliced shallots and sauté until soft and golden brown, about 5-7 minutes. Season lightly with salt and pepper.

Bring salted water to a boil. Add the sliced new potatoes and cook for 5-8 minutes until tender but still holding their shape. Drain and let cool.

Preheat your oven to 200°C (400°F). Roll out the puff pastry on a lightly floured surface to fit into your tart pan with a little overhang.

Place the rolled pastry into the tart pan, trim the edges, and prick the bottom with a fork.

Layer the cooked potatoes in an even layer, followed by the sautéed shallots, and crumble the Manouri cheese on top.

Beat the egg and use a pastry brush to coat the edges of the pastry.

Place the tart on a baking tray and bake in the preheated oven for 25-30 minutes or until the pastry is golden brown and the cheese is melted.

Allow the tart to cool for a few minutes. Garnish with fresh herbs if desired before serving.