Preheat the oven to 350 degrees F. Place 6, 1-cup glass baking cups in a shallow baking pan and set aside. Place the whipping cream, light cream and vanilla in a small pot and set over medium heat. Bring to just below the boiling point, and then remove from the heat.
Place the egg yolks and granulated sugar in a medium bowl and whisk until the sugar is completely dissolved. Very, very slowly whisk the warm cream into the egg yolk mixture. Strain the mixture through a fine sieve into another vessel with a spout.
Pour the custard into the cups; each should be about 2/3 full.
Set the pan in the middle of the oven, and then pour in enough hot water to come up to the level of the custard in each cup. Bake the custards, uncovered, for 40 minutes, or until the custard is just set but still jiggles. Remove the pan from the oven and carefully lift the cups from the pan onto a cooling rack. Cool the custards to room temperature, and then cover and refrigerate at least
4 hours, or overnight.
To serve, decorate each custard with a mix of fresh berries, and then dust with icing sugar and garnish with mint.