Line the base of a 1.7 L/3 pint loaf tin with greaseproof paper.

Put the egg yolks in a large heatproof bowl over a pan half full of gently simmering water. Using a rotary or hand-held electric mixer, slowly whisk in the sugar until pale and thick. Remove from heat and stir in lime zest and juice.

Whip the cream until standing in soft peaks and fold into the lime mixture.

In a clean, dry bowl and using

clean beaters, whisk the egg whites until standing in soft peaks. Using a large metal spoon, fold the egg whites into the lime mixture.

Sprinkle a thin layer of biscuit crumbs over the base of the tin. Carefully pour in the lime mixture and top with a layer of the remaining biscuit crumbs.

Cover with foil, then place in the freezer compartment of the

refrigerator or in the freezer and freeze for about 8 hours, or overnight, until firm.

To serve: uncover the tin, then run a palette knife around the edges of the pudding to loosen it. Turn out on to a flat serving plate and remove the greaseproof paper. Decorate the pudding with slices of lime and serve at once.