While the mixture chills, blanch the basil and cilantro. Prepare an ice water bath and bring a small pot of water to a boil. Immerse the basil and cilantro in the boiling water for about 1 minute, and then transfer the herbs to the icy bath.
In a blender, add 1/4 cup of the coconut puree and the lemon grass and blend until smooth. Next, add another 1/4 cup of the coconut puree, the coconut rape, ginger and kaffir lime leaves and blend until smooth. Finally, add the blanched herbs and the remaining 1/4 cup coconut puree and blend until the mixture turns a light vibrant green. If at any point the mixture feels warm, transfer it to the freezer to cool off; this will keep the herbs from turning brown. Transfer 1/2 cup of this mixture to a small bowl and whisk in the cream.
Preheat the oven to 350 degrees F.
In a heavy-duty mixer fitted with a paddle attachment, mix together the chilled dry scone ingredients and diced butter on medium-low speed until the butter has broken down into pea-size pieces. Mix in the coconut flakes, dried mango and crystallized ginger. Next add the green herb-cream mixture in 1/4-cup increments until just incorporated, being careful not to over-mix the dough.
Turn the dough out onto a lightly floured work surface and roll out 1 1/4 inches thick. Cut into 3 1/2-inch squares, and then cut each square on the diagonal, forming two triangles per square. Place the triangles on a baking sheet. Brush the top of each triangle with the egg wash, and then garnish with a thin layer of coconut rape.
Bake the scones until golden brown and firm to the touch, 30 to 40 minutes.