Adapted from Canning & Preserving with Ashley English: All You Need to Know to Make Jams, Jellies, Pickles, Chutneys & More (Lark Books)
Try this curd atop currant scones, tucked into pastry shells, or sandwiched between layers of poppy-seed cake. Yield: 3 half-pints
1¼ cups superfine sugar
10 tablespoons unsalted butter, chilled
2 tablespoons Cointreau
Wash and dry the clementines, then zest them, taking care to avoid removing any pith along with the zest. Juice the fruits and strain the juice through a fine-mesh sieve to remove any membranes or seeds. Set the zest and juice aside.
Place the eggs in a medium-sized metal bowl and beat lightly to incorporate the whites into the yolks.
Fill a medium saucepan with about 2 inches of water, and place it over medium heat. Bring to a gentle simmer. Place the egg bowl on top of the pan to form a double boiler, and add the sugar, butter, Cointreau, juice, and zest. Whisk gently until the sugar dissolves and the butter melts. Stir the mixture with a wooden spoon until it thickens and coats the back of the spoon, about 8 to 10 minutes.
Remove the curd from the heat. Transfer the curd to heat-proof jars. Allow to come to room temperature, then cover with lids and store in the refrigerator. Consume within two weeks.
*Variation: To make this curd without alcohol, replace the Cointreau with orange juice. You can also substitute mandarin oranges for clementines.