Chocolate and Lavender Tart

For the Pastry:

• 50 g/1¾ oz/3½ tbsp chilled unsalted butter, diced

To make the pastry, combine the butter, flour and salt in a food processor and pulse until the mixture resembles breadcrumbs. Add the sugar, egg and cold water and pulse again to incorporate the egg. Scrape out the pastry and knead gently to form a firm dough. Wrap in cling film (plastic wrap) and chill for at least 30 minutes.

Roll the pastry out to 3mm/ 1/8in thick on a lightly floure