Sterilize a heatproof jar or bowl so it's ready to receive the hot oil; set aside.
In a small dry skillet, lightly toast the White Sesame Seeds until they turn golden and release a nutty aroma; transfer to a heatproof bowl and let cool.
Combine the toasted seeds with the Chinese Chili Flakes, Ground Sichuan Pepper, a pinch of Fine Salt and a little Sugar in the bowl—stir to distribute evenly.
Roughly chop the Scallions, smash the Garlic cloves and slice the Ginger into thin rounds so they release maximum flavor during infusion.
Pour your Neutral Oil into a small saucepan and add the whole spices: Star Anise, Cassia Cinnamon Stick, Dried Bay Leaves and Sichuan Peppercorns.
Gently heat the oil over medium-low, allowing it to come up to a steady shimmer so the aromatics sizzle gently—do not let it smoke. Maintain this for 5–10 minutes until the oil is richly fragrant and the scallions, garlic and ginger have softened and browned slightly.
Remove the pan from the heat and let the oil steep with the aromatics for another 10 minutes to deepen the flavor.
Strain the oil through a fine-mesh sieve into a heatproof pouring vessel to remove the large aromatics and whole spices (reserve a few crisped scallion or garlic bits if you like for texture).
Carefully pour the hot oil over the bowl of chili flakes and sesame seeds; it should sizzle and bloom the spices—stir gently to combine and release the colors and aromas.
Let the mixture cool to room temperature, then transfer to the prepared jar. The flavors will continue to meld over 24–48 hours; store refrigerated or in a cool pantry and use within several weeks.
