Method

1. Place shortbread biscuits in a freezer bag
2. Seal and bash with a rolling pin to make fine biscuit crumbs. Set aside
3. Chop up leaf gelatine into fine strips with scissors and place in a jug with the water for 5 minutes to soak
4. Meanwhile place the lemon juice and rind, sugar and egg yolks in a medium size solid base pan. Do not use non-stick as you need to beat the mix with metal beaters.
5. Place pan over a gentle low heat and whisk using an electric mixer for 5 minutes or just until the sauce thickens slightly to a light custard
6. Allow to cool. (Placing in the freezer for 10 minutes is the best method.)
7. Place soaked gelatine in its jug over simmering water until the gelatine runs clear and is completely dissolved
8. Whisk into the cooled custard
9. Wash and thoroughly dry beaters and whisk egg whites until stiff (you should be able to turn the bowl upside down without losing its contents!)
10. Beat the double cream until just thick using the same beaters (no need to wash in between if whisking egg whites first)
11. Gently stir cream into the lemon custard and then gently fold in the whisked egg white using a metal tablespoon
12. Spoon flummery into the bottom of 4 glasses
13. Sprinkle on shortbread crumble
14. Repeat finishing with a flummery layer
15. Chill until required
16. Decorate with the lemon slices and mint leaves
17. Best eaten on day of preparation for ultimate fluffiness.