1. Bring the milk and cream to a boil with the split, scraped vanilla bean. Let infuse for 10 minutes, then strain.
2. In a large bowl, beat the egg yolks and powdered sugar until the mixture is pale and light. While still stirring, slowly mix in the vanilla-infused milk. Return the mixture to the saucepan and add the ground pistachios.
3. Heat over low heat, stirring constantly. Once the mixture coats the back of a spoon, it is ready.
4. Strain the cream into a bowl and add the crushed pistachios to thicken. Cool by placing the bowl into a container filled with ice. Stir occasionally, cover with plastic wrap and refrigerate.
5. Meanwhile, beat the egg whites to stiff peaks with a pinch of salt . Bring the milk to a boil, then reduce the heat to a low simmer.
6. Place a tablespoonful of egg whites into the hot milk, cook for 2 minutes, turning occasionally, and repeat the process until the egg whites are used up. As each meringue is cooked, transfer it to paper towels to drain. set aside.
7. Just before serving, make the caramel by heating the water and granulated sugar in a saucepan. Stir with a wooden spoon and wipe down the sides of the pan with a wet brush to prevent the formation of crystals. Bring to a boil and stop the cooking once the caramel is blond.

Assembly

1. Pour the pistachio cream into dessert cups.
2. Add a "floating island" meringue.
3. Decorate with drizzles of caramel.