Since this recipe includes the egg yolks, which are not cooked, it's important that you choose only fresh eggs. Don't be tempted to use up eggs that have been lying round in your fridge for weeks! Separate the egg yolks and whites. Whip the egg whites until they are stiff. Whip the cream until it doubles in volume (it doesn't have to become stiff). Grate the zests from the limes and the mandarins then, in a large mixing bowl, whip together the egg yolks, both types of sugar and the zests. Add the cream then gently stir in the egg whites. Empty the contents into a sealable container and leave in the freezer for at least 12 hours.
There are many ways to serve Citrus Parfait. What we do is place an ice cream scoop of parfait into each individual dish, drizzle a little liquid caramel over, sprinkle two or three pecan nuts on top then decorate with a 'speculoos' caramelised biscuit (Lotus Original Caramelised Biscuits are generally available). Our guests usually scream for more (unless they are too polite, but we don't know many people like that!)
If you have plenty of space in your freezer, there's no reason why you shouldn't divide the mixture among silicon muffin moulds instead of freezing in one container. When ready to serve, reverse the silicon muffin mould on a serving plate and sprinkle with lemon zest, serve immediately with blueberries or other fruits you may like. Alternatively, you can freeze in dessert cups and then decorate the tops with fruits and lemon zest too... lots of options for this lovely dessert.