Step 1Place the cream, milk and ginger in a large heavy saucepan over medium heat and heat until bubbling, 4 to 5 minutes. Remove from the heat and allow to sit, covered, for 30 minutes to infuse the flavor from the ginger.
Step 2After the cream mixture has steeped, whisk the egg yolks and eggs in a large mixing bowl slightly to mix. Add the sugar and stir thoroughly until the mixture is uniform and there are no dry lumps of sugar. Don't whip air into this mixture. Stir in the vanilla extract.
Step 3Heat the cream mixture to scalding again. Remove from the heat and temper it into the egg mixture by adding it gradually and stirring each addition in thoroughly to avoid scrambling the eggs. Strain the finished liquid through a very fine strainer or cheesecloth to remove the ginger and any bits of cooked egg which will mar the texture of the finished custard.
Step 4Heat the oven to 300 degrees. Divide the mixture into 8 (6-ounce) ramekins. Set the cups into a roasting pan about 3 to 4 inches deep. Add boiling water to the pan to immerse the cups halfway. Cover the pan with foil and poke a few holes in the foil with the tip of a knife. Place the pan in the oven and bake until the outside two-thirds of the custard is set and the center of each jiggles slightly when the cup is tapped, 1 hour 30 minutes to 1 hour 45 minutes. Remove the cups from the water bath and allow to cool at room temperature for about 45 minutes. Refrigerate, covered with plastic wrap, until completely chilled before serving, about 2 hours.