• Remove the peel from 1 of the limes (in large pieces). Remove the zest from the other lemon and squeeze it to recover its juice.
• In a bowl, mix 50 g of sugar and the juice of 1 lime. Add the peach slices, rosemary sprigs and lime peel. Filter and let marinate for 1 to 2 hours (at least 40 min).

Preheat your oven to 180°C (350°F)

• Drain the peaches and collect the juice, set aside.
• Roll out the puff pastry on a floured work surface. Form a disk about 26 cm in diameter and 0.5 cm high (I do it by eye), and transfer to a baking sheet covered with parchment paper.
• Spread the drained peach slices over the surface of the dough, leaving a small border on all sides (about 5-6 cm). Fold the sides over the peaches.
• Brush the dough with beaten egg and sprinkle with 1 to 2 tablespoons of sugar. Bake for 20 minutes.
• Meanwhile, mix cornstarch with peach juice in a saucepan. Bring to a boil and allow to thicken to a syrupy (honey-like) consistency.
• Take the tart out of the oven, pour the syrup over the fruit and sprinkle with chopped rosemary. [this is also when Ottolenghi puts the butter cubes on the fruit, but I don't add them].
• Return to the oven for 15 minutes. Let it cool and enjoy.