Combine the dry ingredients: In a heatproof bowl, mix together the red chili flakes, paprika, salt, five-spice powder, and sesame seeds.
Infuse the oil: In a small pot over medium heat, add the oil, ginger, scallions, and smashed garlic. Cook until aromatic, about 2 minutes, then remove the solids to avoid burning.
Make the chili oil: Heat the oil to around 325°F (163°C). Use a multi-step pour: Start by pouring one ladle of hot oil into the chili flake mixture and whisk immediately. Then slowly pour in the rest of the hot oil and whisk again. Add the Chinkiang vinegar at the end to cool the oil and balance the flavors.
Store: Transfer the chili oil to a clean, sterilized airtight container. Store in the refrigerator for up to 6 months.
