Place the raspberries and red currants in a blender or food processor and blend until pureed.
In a stainless steel saucepan, bring the wine to a boil. Add the raspberry and red currant mixture, 2 tablespoons of the sugar, and the vanilla bean. Simmer over low heat for 10 minutes. Add the cornstarch, stir, and gently bring to a boil. The pudding should thicken somewhat but still be rather loose. Add more sugar to taste if necessary. Add the strawberries, bring to a boil, and remove from heat. Transfer to a bowl, cover, and refrigerate for at least 1 hour.
Spoon the pudding into individual bowls. Sprinkle with slivered almonds and serve the cream in a pitcher on the side.