Heat a first part of the cream (140 g) and pour over the white chocolate to melt it, then blend.
Meanwhile, combine the grapefruit puree, rosewater, and Ispahan puree, stir in the sugar and heat to 70°C.
Pour over the gelatine mass to melt it, then add to the puree.
Stir the white chocolate ganache into the puree, then add the rest of the cold cream (1260 g), mascarpone, almond paste, grapefruit zest and rose petals.
Blend using a hand blender, then strain the mixture into a container, cover the surface with plastic wrap.
Refrigerate overnight before using.
In a saucepan, heat the pink guava puree and water to 30°C.
Stir in the combined agar-agar and sugar and boil for 2 minutes.
Let the mixture cool down then blend with a hand blender to obtain a soft, smooth jelly.
Add the rosewater, then stir in the diced soft dried guava.
Combine the milk, egg yolks and sugar then mix with the grapefruit puree and rosewater.
Make a custard with the mixture, then add the gelatine mass.
Let cool.
When below 60°C, blend in the butter and emulsify.
Melt the white chocolate with the cocoa butter.
Add to the combined feuilletine, streusel and guava paste.
Using a laminator, make a Æ12.5-cm disc.
Heat the eggs, yolks, sugar and honey to 38°C.
Meanwhile, beat the egg whites and sugar to the stiff peak stage.
Whip the egg yolk mixture to the soft peak stage, fold in 1/3 of the meringue, then fold in the sifted flour and remaining meringue.
Heat the butter to 50°C to melt, then add to the batter and pour into a baking tray.
Using the paddle attachment, combine all the ingredients.
Work through a coarse sieve.
Bake the crumbs in a 165°C oven for 25 minutes.
Heat the white chocolate and cocoa butter to 40°C to melt.
Mix in the food colourings using a hand blender.
Cut out a disc of almond sponge using a Æ12-cm round cutter.
In a Æ12-cm silicone mould, line the bottom with a layer of guava jelly, then pour in the grapefruit cremeux and place the disc of sponge on top.
Top with the guava crunch.
Freeze until set.
Whip the grapefruit rose ganache, fill the mould with the ganache, reserving some for the decoration, then return the insert to the freezer until set.
Unmould.
Using a Saint Honoré tip, pipe the remaining whipped ganache into a dome shape on the sides and top of the frozen insert.
Return to the freezer until set.
Spray the dessert with the velvet mixture and decorate the centre with fresh guava slices and rose petals.