Combine the cream, 1 oz/30 g of the sugar, and the grated orange zest in a saucepan and bring to a boil. Remove from the heat, cover, and steep for 5 minutes.
Blend the egg yolks with the remaining 1 oz/30 g sugar to make the liaison. Temper by gradually adding about one-third of the hot cream mixture, whisking constantly. Add the remaining hot cream.