In a medium bowl, combine the Chinese five spice powder, dry sherry, soy sauce, honey, hoisin sauce and oyster sauce. Stir until all ingredients are well combined.
Heat a small saucepan over medium heat and add the sesame oil. Once the oil is hot, add the Char Siu Sauce mixture to the pan and bring to a simmer. Simmer for 3-5 minutes or until the sauce has thickened slightly.
Remove from heat and let cool before serving or storing in an airtight container in the refrigerator for up to one week.