Β½ lemon, zest only, in large pieces
1 orange, zest only, grated, plus extra for serving
300²µ/10Β½΄Η³ϊ arborio rice
40²µ/1Β½΄Η³ϊ raisins
200g/7oz sugar
1 vanilla pod
50ml/2fl oz orange liqueur
5 large free-range eggs, separated
1.7 litre/3 pints milk