Stir together all ingredients except sugar in a bowl.
Cook sugar in a saucepan over medium heat, until it begins to melt. Continue to cook, stirring occasionally with a fork, until sugar is melted into a deep golden caramel.
Tilt pan and carefully pour in hoisin mixture. Cook over low heat, stirring, until caramel is dissolved and sauce is thickened, 6 to 8 minutes.
Cool to room temperature. Serve with shrimp, swordfish, pork, or chicken.
