Place the gelatin
, water, liquid glucose and white fat in a heatproof
bowl over a saucepan of hot water until melted,
stirring occasionally. Remove the bowl from the heat.
Sift the
icing sugar and gum tragacanth into a bowl. Make
a well in the centre and add the egg white and
the gelatin mixture. Mix together to form
a soft malleable white paste.
Knead on a
surface dusted with icing sugar until smooth, white
and free from cracks. Place in a plastic bag or wrap
in clear film, sealing well to exclude all the air.
Leave for about two hours before use, then knead
again and use small pieces at a time, leaving the
remaining petal paste well sealed.