In a small saucepan, gently warm the coconut milk and maple syrup, stir in a pinch of salt.
In a blender, combine the oat milk, lemon juice, zest, vanilla, cornstarch and agar agar and blend until smooth.
Bring coconut milk to a simmer and then add the mixture from the blender while you whisk.
Bring to a boil for 3 minutes, continue to whisk. Remove from the heat and let cool to room temp.
Remove crust from freezer and add sliced berries or spread the crust with jam.
When the filling has cooled, pour over the berries and crust and refrigerate for at least four hours or overnight.
Garnish with fresh berries on top or drizzle with thinned jam.