Preheat oven to 180C. Turn on ice cream machine to chill. Turn on pressure cooker to warm.
For the Smoked Rice Ice Cream, place rice, 250ml of the milk and 30g of the sugar into the pressure cooker. Seal the pressure cooker, turn on to high and cook for 8 minutes. Once cooked, remove from the pressure cooker and transfer to a blender. Process to coarse purée with some small granules of rice still remaining. Set aside to cool.
Place the egg yolks and 40g of the caster sugar into a medium bowl and whisk until pale.
Place the remaining 200ml of milk, cream, remaining 40g of the caster sugar and the vanilla seeds and pod into a small saucepan over medium heat and heat until just simmering. Remove from the heat and discard the vanilla pod.
While whisking, slowly pour the hot milk and cream mixture into the egg yolk mixture, whisking continuously. Return the mixture to the saucepan and heat over low heat to until the mixture thickens slightly and coats the back of a spoon. Strain the anglaise through a fine sieve into a medium mixing bowl and place over an ice bath to cool.
Once cool, cover the bowl with cling film and seal tightly. Insert the hose of a smoking gun and seal the cling film tightly again. Light the smoking chips and allow the bowl to fill with smoke, then remove the hose and seal the cling film again tightly. Set aside to smoke for 10-12 minutes. Uncover the bowl and fold in the reserved rice purée, then place into the ice cream machine and churn until set, about 30 minutes. Once set, transfer to the freezer until needed.
For the Milk Skin, place the milk and sugar into a large roasting dish and whisk to combine. Place the tray into the oven and cook until a golden skin has formed on top, about 18-20 minutes.
Meanwhile, line a baking tray with baking paper.
Remove the roasting tray of milk from the oven and carefully lift and drag the milk skin onto the lined baking tray. Using a fine grater, grate the nutmeg over milk skin and set aside.
For the Soured Apple, peel the apples, reserving the skin for later use.
Cut the apple flesh into 5mm cubes and place into a small saucepan with the vinegar, sugar and 30ml water. Place over a medium heat and bring to the boil, then reduce heat to low and simmer gently until apple pieces are just tender, about 8-10 minutes.
For the Smoked Apple Chips, Lay the reserved apple skin out onto a baking tray lined with baking paper and place into the oven to bake until slightly dried and brown around the edges, about 8-10 minutes.
Remove from the oven and transfer skins to a small bowl. Cover bowl with cling film and seal tightly. Insert the hose of a smoking gun and seal the cling film again. Light the smoking chips and allow the bowl to fill with smoke, then remove the hose and seal the cling film again tightly. Set bowl aside to smoke for 10 minutes then uncover the bowl and set aside.
For the Roasted Walnuts, spread walnuts onto a baking tray lined with baking paper and roast in the oven until golden, about 8-10 minutes. Remove from the oven and break into small pieces. Set aside to cool.
To serve, first scatter Soured Apple in a ring around centre of each serving plate. Scatter some Roasted Walnut pieces around the Soured Apple. Garnish with fennel fronds and edible flowers. Top with a scoop of the Smoked Rice Ice Cream in the centre of the Soured Apple pieces. Top with some pieces of Milk Skin and finish with Smoked Apple Chips.