How to Make It
In a heavy-bottomed medium saucepan, combine the sugar, lemon juice and 1/4 cup of water and bring to a boil. Using a wet pastry brush, wash down any sugar crystals on the side of the pan. Boil undisturbed over moderately low heat until a deep amber caramel forms, about 20 minutes.
Stir in the shallots, chile, star anise, cinnamon and pepper. Remove the saucepan from the heat and carefully whisk in the fish sauce and 1/4 cup of water. Stir over moderate heat until the caramel is dissolved. Pour the sauce into a heatproof bowl and let cool completely. Remove the chile, star anise and cinnamon stick. Use immediately or refrigerate.
The caramel can be refrigerated in a lightly sealed container for up to 2 weeks.