Preheat oven to 350 degrees F (177 degrees C).
Split vanilla bean in half lengthwise. Place bean cut sides up and with the back of a knife, scrape out the seeds the entire length of the bean, set side.
In a medium bowl, whisk egg yolks until combined. In another medium bowl, add 3/4 cup coconut milk, place a strainer over bowl, set aside.
In a saucepan over medium heat, add another 3/4 cup coconut milk, stevia and vanilla, seeds and bean. Heat milk mixture just until it begins to steam, do not simmer. Pour warm milk mixture into bowl of egg yolks, whisk to combine.
Now strain the milk/egg mixture into the other bowl of coconut milk, whisk to combine.
Pour custard mixture into 4 custard cups. Place cups in a deep pan. Pour hot water, not boiling, into the pan until it reaches halfway up the sides of the custard cups. Cover pan with foil and seal tightly. Bake custards for 25 to 30 minutes, until edges are firm but still soft in the centers.
Remove custards from pan, cool. Serve at room temperature or chilled, with a garnish of flaked coconut.