01 - Combine chopped dates and water in a small saucepan. Cook over low heat for 3-4 minutes, stirring constantly until dates soften into a jammy consistency. Remove from heat and allow to cool completely to room temperature.
02 - In a large chilled bowl, whip cold heavy cream using an electric mixer or whisk until soft peaks form. Refrigerate immediately to maintain structure.
03 - Whisk egg yolks with granulated sugar in a separate bowl until mixture becomes pale yellow and thickened, approximately 3-4 minutes. Incorporate orange blossom water and lemon zest until fully combined.
04 - Process cooled date mixture in a food processor or blender until smooth paste forms. Gently fold date paste into egg yolk mixture until uniform in texture.
05 - Gently fold chilled whipped cream into date-yolk base in two separate additions, using a spatula with light folding motions to maintain airiness and prevent deflation.
06 - In a thoroughly clean bowl, whisk egg whites until stiff glossy peaks form. Carefully fold whipped whites into mousse base using gentle lifting motions to preserve maximum volume.
07 - Distribute mousse evenly among individual serving glasses or bowls. Refrigerate for minimum 2 hours or until completely set and firm.
08 - Top each serving with chopped pistachios, freshly grated orange zest, and sliced dates. Serve chilled alongside buttery shortbread or Lebanese semolina cookies for added texture contrast.