Put the single (light) cream and nuts in a blender and blend until the nuts are pureed. Spoon the mixture into a small saucepan and stir in the double (heavy) cream. Place over low heat and simmer gently until the mixture is hot. Remove from the heat, cover and set aside to cool.

Pour the mixture into a medium-sized bowl, beat in the almond essence (extract) and set aside.

Beat the egg yolks until they are well blended.

Dissolve the sugar in the water over low heat, stirring constantly. Increase the heat to moderate and boil the syrup until the temperature reaches 140°C (220°F) on a sugar thermometer or until a little of the syrup spooned out of the pan and cooled will form a short thread when drawn out between your index finger and thumb. Remove from the heat and let the syrup stand for 1 minute.

Pour the syrup over the egg yolks in a steady stream, whisking constantly. Continue whisking until the mixture is thick and fluffy. Mix in the cooled cream mixture, then fold in the beaten egg whites.

Pour the mixture into an ice-cream container equipped with paddles or into a hand-propelled ice-cream churn, and freeze according to manufacturers' instructions.

Store in the frozen food storage compartment of the refrigerator and serve as required.