Heat coconut milk, soy milk, mint leaves, and sugar over medium low heat in a saucepan. Whisk until the sugar is fully combined. Make sure your milks don't boil.
Remove the mint leaves using tongs or a fork.
Remove about ½ cup of the coconut milk and pour into a medium bowl. Add 4 tbs of corn starch and whisk until fully combined.
Add the corn starch slurry back to the pudding. Continue whisking until the slurry is mixed into the coconut milk, and turns shiny. The custard should thicken, but will thicken more in the fridge. Take the custard off the heat and transfer into a bowl.
Fold in the vanilla, pinch of salt, and the citrus zest.
Place it in the fridge overnight, or until fully cooled.
Optionally top with fresh fruit, extra zest, or coconut whip.