Pour 3 cups of neutral oil into a heavy bottomed saucepan. Add the Sichuan peppercorns, garlic, shallot, cinnamon stick, bay leaves, star anise, and cloves. Turn the heat to medium low.
Heat over medium low until the neutral oil temperature up to 225-250F and infuse your spices for 30 minutes, or until the aromatics are a deep golden brown. Monitor the temperature of oil so it stays in this temperature range. Turn off the heat.
In a large ceramic or heavy metal mixing bowl (do not use glass), add the Sichuan chili flakes. Ensure that the bowl has at least 5 inches of clearance between the chili flakes and the rim of the bowl.
Strain all of the spices from the oil with a mesh strainer and discard the spices. Turn the heat to high and heat the oil to 350F. Turn off the heat, then carefully pour the oil directly over chili flakes in a steady stream.
Mix the oil and chili flakes to combine, then add the sesame seeds, sugar and salt. Let cool completely and store in an airtight container for up to 3 months.
