Preheat oven to 300°. Combine citrus juices in a heavy bottomed pot and reduce to approximately 1/8 cup – should be very tart. Heat heavy cream and sugar until sugar completely dissolves. Set aside.

Beat egg yolks slightly. Gently mix in citrus reduction and heavy cream mixture. Strain mixture through a fine strainer. Divide into six 5 oz. ramekins. Set ramekins in a baking dish and pour enough hot water around ramekins to come halfway up the sides. Place in 300° oven for 1 ½ hours until just set. Let cool in water bath 10-15 minutes. Remove and cool completely. Refrigerate at least 4 hours before serving.

To serve, cover with brown sugar and caramelize under broiler. Serve immediately.