In a large heat-safe bowl, combine the crushed chili flakes, sesame seeds, salt, and sugar; stir to mix evenly.

Place a small heavy-bottomed saucepan over medium-low heat and add the neutral oil, star anise, cinnamon stick, bay leaves, and Sichuan peppercorns.

Add the smashed garlic cloves, green onion whites, and ginger slices to the cool oil.

Warm the oil slowly, letting the aromatics gently sizzle for 10–12 minutes until the temperature reaches 275–300°F (135–150°C); avoid exceeding 300°F to prevent burning.

Remove the saucepan from heat and strain out all solid aromatics using a fine-mesh strainer, leaving clear, flavored oil.

Carefully pour one-third of the hot oil over the chili base; it should sizzle vigorously. Stir gently to bloom the spices.

Pour the second third of the oil over the mixture, stir again, then add the remaining oil and mix until the chili flakes are evenly toasted.

Let the chili oil cool completely at room temperature for about 60 minutes, allowing flavors to develop.

Transfer the cooled chili oil, including the flavorful sediment, to a clean glass jar with a tight-fitting lid. Store in the refrigerator for up to 6 months and shake before each use.