Bring the sugar and fresh orange juice to a boil in a saucepan over medium-high heat, stirring until the sugar dissolves. Keep the mixture at a rolling boil so it looks glossy and bubbling around the edges.

Add the fresh cranberries and salt to the boiling liquid. Simmer for 10 minutes, stirring occasionally, until most of the berries burst and the sauce thickens slightly with visible berry skins.

Remove the saucepan from the heat and stir in the orange zest. The sauce should look fragrant and speckled with small orange flecks.

Let the sauce cool slightly, then gently fold in the orange, peeled and segmented. Stop mixing as soon as the segments are coated to keep them intact.

Chill the sauce until serving. It should thicken as it cools, becoming spoonable with a vivid cranberry-orange color.