Bring vinegar to a boil in a small saucepan; boil 8 minutes or until reduced by half. Remove from heat; stir in ginger and sugar; set aside. Trim tough ends off asparagus. Bring a large pot of water to a boil; add asparagus; cook 3 minutes; remove from heat; drain. Cover with ice water to stop cooking; drain. Arrange on serving platter. Combine garlic, lemon grass, canola oil, soy sauce and chili pepper, if using. Stire in reduced ginger vinegar mixture. Drizzle over asparagus. Serve.