How to Make It
In a small saucepan, combine the sugar, water, corn syrup and tangerine juice. Bring to a boil over moderate heat; do not stir. Boil without stirring until a golden amber caramel forms, 6 to 8 minutes. Wash down the side of the pan with a wet pastry brush if crystals form.
Sprinkle the zest into eight 6-ounce ramekins. Pour the caramel into the ramekins, tilt to coat the bottoms and let cool to room temperature, about 20 minutes.
Preheat the oven to 350°. In a medium saucepan, warm the milk and cream over moderate heat until the mixture reaches 160° on an instant-read thermometer, 5 to 7 minutes. In a medium heatproof bowl, whisk the eggs with the egg yolks, sugar, vanilla, orange zest and salt. Gently and gradually whisk in the warm milk mixture, to prevent foaming. Strain the custard into a large measuring cup.
Lay a kitchen towel in a roasting pan and set the ramekins on the towel. Pour the custard into the ramekins. Add enough boiling water to the roasting pan to reach halfway up the sides of the ramekins. Tent the pan loosely with foil and bake the custards for about 40 minutes, until just set but still jiggly in the center. Transfer the ramekins to a rack and let the custards cool to room temperature, then refrigerate until cold.
To unmold, run a sharp paring knife around the inner edge of each ramekin to loosen the flan. Invert a plate over the ramekin and flip it over; shake or gently tap the ramekin to release the flan and caramel sauce.