Prepare the orange zest chocolate mousse well in advance and chill until firm for the best texture.
To supreme the fresh oranges, use a sharp knife to slice off both ends, revealing the flesh. Stand the orange on a cutting board with a groove to catch juices, and carefully remove the peel, cutting close to the flesh to avoid any white pith. Slice between each segment to free the supremes from their membranes. Collect all juices and store the segments in an airtight container.
Squeeze juice from the 4 oranges and combine with the collected juices. Strain through a fine cloth for clarity, sweeten to taste with sugar syrup, and chill.
Reheat the puff pastries (or bake fresh). While hot, slice each lengthwise. Place the bottom half on the plate, mound with chocolate mousse. Fan orange supremes at the base, then drizzle orange syrup between segments to pool elegantly on the plate.
Top with the warm pastry lid and serve immediately for a perfect contrast of textures.
*Orange Zest Chocolate Mousse: Start with a classic chocolate mousse recipe. Purchase candied orange zest from a trusted confectioner or pastry shop. Soak in hot water for 1 hour to soften, pat dry, and finely dice into tiny pieces (salpicon). Fold into the finished mousse with Grand Marnier, ensuring even distribution.
Source: Chocolate by Martine Jolly
