In a medium mixing bowl, combine your minced garlic, minced red onion, soy sauce, five-spice powder, salt, Shaoxing wine, sesame oil, and neutral cooking oil. Stir everything together until well combined—you want the salt to dissolve into the liquid and all the aromatics to be evenly distributed. This shouldn't take more than a minute of stirring.
Here's what's happening: the soy sauce and Shaoxing wine are your liquid components, and they're carrying flavors into the meat. The oils are emulsifying slightly, creating a cohesive marinade rather than separated components. The garlic and onion are releasing their natural sugars and sulfur compounds, which will caramelize slightly when the chicken roasts.