Preheat the oven to 275 degrees F.
In a small saucepan combine the milk, cream, and lemon zest and heat until milk just begins to turn foamy on top. Set aside for 5 to 10 minutes.
Place the chives and warm milk in a blender and puree until smooth. Strain through a fine mesh sieve and discard solids. Add salt and white pepper, to taste.
In a small bowl, lightly whisk the egg yolks. Add the milk in a steady stream, whisking gently to combine. Transfer the custard into a 4-ounce ramekin. Place the ramekin in another baking dish just large enough to hold it (a loaf pan should work well for this) and fill the pan with enough hot water to reach 1/2 way up the side of the ramekin. Cover with foil and bake for 45 minutes to 1 hour, depending on your ramekin, or until the custard is set but still slightly jiggly in the center. Remove from the oven and allow to cool in the water bath for 10 minutes.
Garnish with a dollop of caviar, creme fraiche, and chives. Serve warm with French Bread Crostinis.
Yield: 1 flan, 2 servings