- 2/3 cup sugar
- 1/4 cup water
- 1/2 teaspoon anise seeds
- 1/3 cup balsamic vinegar
- 4 navel oranges
- Bring sugar, water, and anise seeds to a boil in a 1- to 1 1/2-quart heavy nonreactive saucepan, washing down any sugar crystals on side of pan with a pastry brush dipped in cold water and stirring until sugar is dissolved. Boil syrup, without stirring, gently swirling pan, until mixture is a golden caramel. Reduce heat to low and carefully stir in vinegar (mixture will steam vigorously and caramel will harden). Stir until caramel is dissolved, about 1 minute.
- Cut peel, including all white pith, from oranges with a sharp knife, then slice oranges crosswise. Serve orange slices drizzled with warm sauce.