Combine 150 ml soy milk with the cornstarch, mix well, then heat over a double boiler. Once it thickens, chill it in an ice bath.
If additive-free cornstarch is hard to find, you may use rice flour for baking.
Once the soy milk cools, add the remaining 50 ml soy milk and the sugar, then whip until the cream forms a thick ribbon when lifting the whisk.
Microwave the kirschwasser for 30 sections to evaporate the alcohol; this will be added to eliminate the soy milk odor.
While the kirschwasser is still hot, gently stir in the palm oil, almond oil, lemon juice, and vanilla oil; it doesn't have to be evenly combined.
Add the mixture from Step 5 to the soy milk mixture and whip until it forms soft peaks form.
Dissolve the kanten in 50 ml boiling water. If adding fruit with a high water content, then microwave to heat, then dissolve the kanten in the fruit juice.
Whip in the kanten liquid while still hot. Once it is mixed in, stop whipping, then chill.
Mix in the fruit, chill in a mold, or chill to use as cake filling.
Story Behind this Recipe
Since I was making a Bûche de Noël, I wanted a thick and substantial dairy-free filling. That's how I came up with this fruit mousse without the odor of soy milk. Since gelatin is typically derived from a bovine source, I used kanten to make it vegetarian.
The fluffiness of the mousse is essential. If you make a mistake in the amounts or process, the cream may flatten. In that case, turn it into blancmange, or add and egg yolk and lemon juice, then chill it in a mold to make bavarois. Mixing meringue with the blancmange will give you mousse. If it's too stiff, think of it as a soy milk yokan.