Croissants are not particularly difficult to make, but they do require patience and practice. To achieve a neat crescent shape, it's important to keep the sides of the dough straight and measure accurately.
1 quantity leavened puff pastry
2 egg yolks, whisked with 1½ tablespoons water
1. Use a rolling pin to roll out the pastry on a lightly floured work surface to a neat 35 x 53 cm (14 x 21 inch) rectangle, keeping the edges as straight as possible and rotating the pastry often so you are always rolling away from yourself.
2. Use a large sharp knife to trim the edges so they are straight, forming a 32 x 48 cm (12 3/4 x 19 inch) rectangle, discarding the offcuts. Cut the pastry in half lengthways, making the cut as straight as possible. Don't separate the two strips. Measure and mark 16 cm (6 1/4 inch) intervals along either side of the cut down the centre of the pastry. On the two outside edges, measure and mark the first 8 cm (3 1/4 inches), then mark 16 cm (6 1/4 inch) intervals the rest of the way along. Make straight, diagonal cuts into the pastry to join the marks on each strip and form triangles.
3. Separate each pastry triangle, then elongate each one slightly by giving it a brief roll lengthways with a rolling pin. Working with one triangle at a time, place the short side nearest you and gently stretch the two ends to lengthen slightly. Make a 5 mm (1/4 inch) cut into the base of each triangle, at the centre.
4. Roll the croissant up by rolling the base towards the tip. Turn the roll so the tip of the triangle is facing you, then bend to form a crescent shape.
5. Place on lined baking trays, cover with tea towels (dish towels) and set aside in a warm, draught-free place for 1-1 1/2 hours or until puffed and risen. The croissants will not double in size.
6. Preheat the oven to 220°C (425°F/Gas 7). Brush the croissants all over with the egg wash. Bake for 2 minutes, then reduce the heat to 180°C (350°F/Gas 4). Bake for a further 15-20 minutes or until golden and puffed. Transfer to a wire rack. Serve warm or allow to cool.