Place grapeseed oil for making yuzu caviar in a tall glass canister and place in the freezer to chill.
To make the cassis balls, place cassis puree, water and softened gelatine in a saucepan and set over medium heat. Heat until gelatine has dissolved. Remove from heat, add xantham gum and blitz with a stick blender until well combined, about 2 minutes. Add melted white chocolate and blitz on low setting to combine. Sieve mixture and transfer to a 500ml iSi gun and charge twice. Syphon mixture into 7cm half sphere moulds, sitting on a tray, keeping level with the top of the moulds. Place moulds in the freezer until semi frozen, about 50 minutes.
Once the half spheres are semi frozen, remove from freezer. Scrape out the insides of the spheres, using a spoon, leaving a shell about 5mm thick. Return shells to the freezer.
Meanwhile, to make the syrup for the yuzu rubies, place yuzu juice and sugar in a saucepan and bring to a boil over high heat, allowing sugar to dissolve. Remove from heat. Place 1 tablespoon of the syrup in a sous vide bag. Add diced chestnut and seal, removing as much air as possible. Set sous vide bag aside. Reserve remaining syrup for finished rubies.
To make the plum liqueur jelly, place Choya Shiso and water in a saucepan and bring to a simmer over medium heat. Add gelatine and stir until dissolved. Remove from heat and strain. Pour into a 15cm round tray lined with plastic wrap to a depth of 3-4mm. Place in the fridge to set. Pour remaining mixture into a 19cm round tray lined with plastic wrap and set aside in the freezer to make granita.
To make the cassis pastilles, prepare a small tray by lining with plastic wrap. Place cassis puree in a small saucepan and set over medium heat. Place pectin and 50 gm sugar in a bowl and stir to combine. Add pectin/sugar mixture to the warm puree and stir to combine. Bring puree to a boil, remove from heat, add remaining 100 gm sugar and glucose and stir to combine. Return mixture to a medium heat and allow to simmer until temperature reaches 107C. Remove from heat, stir in citric acid then immediately pour into prepared tray. Allow to sit at room temperature until set. Cut into cubes, toss in sugar, to coat, and set aside.
To make the raspberry crispies, place white chocolate in a bowl and allow to melt on top of a saucepan of gently simmering water. Meanwhile, place rice crispies on a baking tray and place in the oven to toast, about 4 minutes. Remove rice crispies from oven and add to the melted white chocolate. Add raspberry powder and fold to combine. Tip mixture onto a paper lined baking tray and allow to set. Once set, break into pieces and set aside, in fridge.
To make the yuzu caviar, place yuzu juice, agar and sugar in a saucepan and stir to combine. Place over high heat and bring to a boil. Allow to boil for 1 minute. Remove from heat and strain into a jug. Place jug in an ice water bath to allow mixture to cool down to about 35C.
Transfer cooled mixture to a syringe. Remove cold oil from the freezer and holding the syringe above the oil, drop mixture into the cold oil to form pearls. Allow the pearls to sit in the oil for 10 minutes. Strain, discarding oil and set pearls aside in the fridge.
To make the plum liqueur gel, place Choya Shiso and water in a saucepan and bring to a boil. Remove from heat, add xanthan gum and using a stick blender, blend for 2 minutes. Pass mixture through a fine sieve into a squeeze bottle and set aside in the fridge.
To make the yoghurt mousse, place all ingredients in a bowl and whisk to combine. Pass through a sieve into a jug and pour into a 1L iSi gun. Charge twice and set aside in the fridge.
To make the yuzu rubies, bring a small saucepan of water to a simmer. Remove diced chestnut from the sous vide bag, strain and discard syrup. Place the chestnut dice in a bowl, add tapioca flour and toss to coat thoroughly. Place coated chestnut in the simmering water, keeping them separate so that they don’t stick together, and allow to cook until the chestnut dice float to the surface, about 1 minute. Remove from water and place in the reserved yuzu syrup and set aside.
Remove frozen shells from freezer. Heat the back of a tray using a blow torch. Hold 2 shells against the hot tray for 5-10 seconds and then join together to form balls, rubbing the seam to remove.
Heat a 3 cm ring cutter, by holding it with tweezers in front of a blow torch until really hot. Hold hot cutter on top of frozen balls and press very gently to cut a hole in the top of each ball. Set balls aside in freezer.
To make the pink spray, place cocoa butter in a saucepan and set over low heat. Place white chocolate in a bowl. Allow cocoa butter to melt and come to a temperature of 55C. Remove from heat, pour over white chocolate and stir to combine. Add red food colour, gradually, as needed and blend using a stick blender. Add mycro cocoa butter and blend again. Spray temperature should be 30-35C.
Remove cassis balls from freezer and place in the spray booth. Spray balls evenly all over. Return to the freezer.
Remove plum liqueur jelly from fridge and using a 3cm ring cutter, cut out 4 rounds and set aside in the fridge.
Remove plum liqueur jelly from the freezer and, using a fork, scrape it to make granita. Set aside in the freezer.
Strain yuzu rubies from syrup and set aside in the fridge.
To serve, decorate the serving plates with plum liqueur gel. Place 2 tablespoons granita in the middle of each plate. Place a sprayed cassis ball on top of the granita. Place a few rice crispies and blackcurrant pastilles into each ball. Siphon yoghurt mousse into the cassis balls until full. Place a jelly round on top to cover the yoghurt mousse. Sprinkle rice crispies, cubes of blackcurrant pastilles, yuzu caviar, yuzu rubies, flower petals and raspberry powder around the plates.