Put egg yolk, honey, lime peel and juice in top of double boiler. Mix well, then place over simmering water and cook 10 to 15 minutes or until thick and smooth. Stir occasionally during cooking. Remove boiler from hot water and cool, then place in refrigerator for about 30 minutes. In a large bowl, beat egg whites until stiff. Stir about 1/4 of egg whites into chilled lime mix. Then gently fold the lime mix into the remaining egg whites. Fold cream into the mousse. Pour into a large serving bowl or 6 parfait glasses. Cover and refrigerate overnight. To serve, top with nuts.