Blueberry trompe l'oeil entremets

Heat the wild frozen blueberries slowly with sugar and lemon juice; as soon as it boils, cover, take off the heat and leave overnight.

Sieve to separate the juice from the solids; both are used.

For the insert, heat the blueberry juice, add the sugar and agar-agar mixture, bring to a boil and cook two minutes on low heat.

Transfer to a frozen pastry bowl, rest, then refrigerate until completely set.

Rinse the fresh blueberries and pick out stems and bad ones.

Saute wild frozen blueberries, fresh blueberries and some of the saved solids in a hot frying pan.

Smooth the set jelly with an immersion blender and fold in the sauteed blueberries.

Fill two 15-cavity semi-sphere silicone molds, freeze completely, join into spheres and return to the freezer.

For the mousse (ganache montee), boil half the heavy cream, pour over the white chocolate and blend; add the softened gelatin and the saved blueberry solids.

Add the remaining chilled heavy cream, blend well and refrigerate overnight.

Whip the cold ganache montee to soft peaks; keep it soft so it spreads in the mold.

Fill the mold cavities two-thirds full, press in a frozen insert and close the lid, sealed. With one mold, whip half the ganache today and the rest the next day.

Fill the remaining space with ganache montee following the dome shape, leaving no gaps; scrape off the excess and save it for touch-ups.

Freeze overnight until rock solid, then unmold and stand each cake on an upside-down silicone mold. Shave both ends slightly to the shape of a blueberry.

Roll marzipan into paper-thin coins, fold in the edges into crowns, stick on with a dot of leftover mousse and freeze until glazing.

For the enrobage, melt the cocoa butter, take off the heat and add the white chocolate and a tiny bit of dark chocolate.

Transfer to a narrow container, add food coloring to a deep purple and blend; sieve and let cool to 90F (32C).

Dip each frozen cake crown side up, then set crown side down, rotating as it begins to set for a neat finish.

Finish with cornstarch to mimic the blueberry's bloom.