For rhubarb ice-cream, combine rhubarb in a saucepan with lemon juice and half the sugar. Stir occasionally over medium-high heat until sugar dissolves and rhubarb breaks down and thickens (6-8 minutes). Bring cream, milk, vanilla bean and vanilla seeds to the simmer in a clean saucepan over medium-high heat. Whisk yolks and remaining sugar in a heatproof bowl until thick and pale (5-6 minutes), add cream mixture, whisk to combine. Return to pan, stir continuously until mixture coats the back of a wooden spoon thickly (4-5 minutes). Strain into a bowl, stir through rhubarb mixture and refrigerate until cool. Freeze in an ice-cream machine and store in freezer until required. Makes about 1.5 litres.
Preheat oven to 180C. Combine almonds, icing sugar and wine in a bowl, spread on an oven tray, bake until golden (6-8 minutes), cool to room temperature then coarsely crumble. Store in an airtight container.
Increase oven to 200C. Combine rhubarb, sugar, dessert wine, orange rind and juice and ginger in a roasting pan large enough to fit rhubarb snugly and roast, stirring occasionally, until just tender (10-12 minutes). Serve hot with candied almonds and rhubarb ice-cream.