Add the strawberries, lemon juice, and lemon zest to a food processor or blender. Blend until fully pureed. Add in the tapioca starch and blend again to incorporate.
In a saucepan, combine the coconut milk and agar powder. Bring to a simmer and let simmer until thickened. Add the fruit mixture and bring the mixture to a low boil. Let boil until it's thickened to the consistency of a loose pudding, stirring frequently, about 5 minutes. It should be thick and glossy.
Remove from the heat, whisk in the vanilla, and pour into your prepared crust.
Recipe inspired by Bos.Kitchen!