Place gelatine and cold water in a heat-proof bowl and let sit for 5 minutes.

Meanwhile in a small bowl, using an electrical whisk beat the egg yolks and sugar until thick and pale in colour.

In another bowl beat the heavy cream until soft peaks form.

Place the bowl with the softened gelatine over a small saucepan of simmering water to melt gently.

Once gelatine is melted, add lemon juice and zest.

While continuing to beat the egg yolks, slowly add the gelatine/lemon mixture.

Beat the egg whites in a clean bowl until stiff peaks form.

Add the gelatine mixture to the cream before folding in the egg whites.

Pour into a serving bowl and leave in the fridge to set for at least 3-4 hours.