To make sorbet, freeze juice mixture until solid, break into chunks, and pulse in a food processor until smooth.
- 2 cups orange juice (from 5 oranges), plus 2 oranges, peel and pith removed, flesh cut into pieces for serving
- 3 tablespoons maple syrup
- 3 tablespoons light sour cream
- Ground cardamom (optional)
Stir 2 tablespoons syrup and pinch of salt into juice. Transfer to a shallow 2-quart dish. Freeze 2 hours, scraping with a fork every 30 minutes (mixture should icy and fluffy).
Stir together sour cream, remaining tablespoon syrup, pinch of salt, and cardamom if using. Divide among 4 bowls. Top with granita and orange segments.