Ingredients

Step by step

1. First make the clementine curd. Beat the eggs and egg yolks together and strain them into a heatproof bowl, through a sieve. Add the clementine zest, strained clementine and lemon juice (to remove any pips), sugar, butter and cornflour. Rest the bowl over a pan of gently simmering water and cook gently, stirring constantly, for 20-25 minutes until thick, taking care not to let the mixture get too hot. Transfer to another bowl and leave to cool, covering after a while with clingfilm to prevent it from forming a skin. Pour into sterilised jars, seal with lids and store in the fridge for up to 2 weeks. Chill the curd for at least 2 hours before using in the filling.
2. For the roulade, preheat the oven to 160°C, fan 140°C, gas 3. Line a lightly greased 23cm x 33cm Swiss roll tin with baking paper.
3. Whisk the egg whites in a large clean bowl into stiff peaks, then gradually beat in the sugar, 1 tablespoon at a time, to make a stiff and glossy meringue. Whisk in the cornflour and vinegar. Spread the mixture evenly in the prepared tin and bake for 25 minutes, until the surface of the meringue is lightly browned. (It will puff up a lot but don't worry, it will go down when it cools.)
4. Lay a large piece of baking paper onto the work surface and sprinkle it lightly with the extra caster sugar. Lift the still-hot meringue out of its tray and, with the edges of the paper, flip it over onto the sugar-dusted paper. Leave to go cold.
5. To make the candied clementine strips, put the sugar in a small saucepan with 100ml water. Heat gently, stirring until the sugar has dissolved. Pare the clementine zest using a vegetable peeler and cut into thin strips. Add these to the sugar syrup and poach for 10 minutes. Lift the strips out using a draining spoon, and scatter onto a sheet of baking paper. Dust with the extra caster sugar and leave to set.
6. To fill the roulade, carefully peel off the lining paper and spread it with 8 generous spoonfuls of the clementine curd. Go right up to the edges on 3 sides, but only to within 2.5cm of the longer edge furthest away from you. Whip the cream into soft but stable peaks and spread it over the curd. Starting with the long edge closest to you, and using the edge of the paper to help you, roll up the meringue as you would a Swiss roll. Leave the roulade wrapped in its paper and chill for at least 3 hours to hold it in shape. Transport in a sealed plastic container, with an ice pack to keep it cold.
7. To serve, unwrap the roulade, dust it with icing sugar and transfer it to a serving plate. Decorate with the candied clementine strips and serve cut into slices.