In a small saucepan, combine the neutral oil, sesame oil, garlic, ginger, and Japanese leek.
Heat gently over medium-low heat until the garlic and ginger are fragrant and lightly golden, taking care not to burn. With a pair of tongs, remove the ginger and leek. For a non-crunchy rayu, remove the garlic as well.
Remove from heat. Pour the hot oil over a bowl containing the ichimi togarashi and salt. Finish with a small drizzle of sesame oil.
Transfer to an airtight container or jar(s) and store in the refrigerator for up to 6 months.
