While the dough is chilling, make the jam: In a large saucepan, stir together the cranberries, 300 grams granulated sugar, orange zest, orange juice, and 1/4 tsp salt. Place the pan over medium heat and leave until the sugar melts and the juices begin to boil. Turn the heat down a bit lower and leave to simmer and bubble until the jam thickens and the cranberries burst. If you have a candy thermometer, remove the jam from the stovetop when it hits 220°F. If you don’t have a thermometer, you can test the jam on the back of a spoon or a plate. If you draw a line with a spoon through it, the jam should hold its place along the line–not fill it in. Transfer to a glass dish and leave to cool for a bit before transferring to the refrigerator to firm up completely.