Step 1

Place cold water in a medium saucepan. Sprinkle with gelatine. Stand for 1 minute to allow gelatine to soften. Place pan over medium heat. Cook, stirring for 1 minute or until gelatine has dissolved. Add sugar and tonic water. Stir over heat, without boiling, for 2 minutes or until sugar dissolves. Remove from heat.

Step 2

Stir lemon juice and gin into gelatine mixture. Strain into a heatproof jug. Stand at room temperature for 20 minutes to cool. Refrigerate for 1 hour or until just starting to thicken (see note).

Step 3

Meanwhile, use the rim of 6 x 1 1/2-cup-capacity serving glasses to cut 6 rounds from sponge. Carefully push one sponge round into the bottom of each glass.

Step 4

Combine custard and lemon curd in a bowl. Divide custard mixture evenly among glasses. Refrigerate while jelly is thickening.

Step 5

Fold cucumber into jelly. Spoon mixture over custard in glasses. Refrigerate for at least 2 hours or until set.

Step 6

Dollop trifles with cream. Top with cucumber ribbons and sprinkle with lemon zest. Serve topped with mint leaves.