To a large saucepan add the first 12 ingredients. Bring to a simmer (225°F - 250°F). Turn heat off and steep for 1 hour (See Note 4), uncovered.
Turn heat up to medium-high to reach 375°F.
While oil is heating up: to a large heat proof bowl add the Sichuan chili flakes, toasted white sesame seeds and salt, stir to combine. Set aside.
Carefully strain the HOT oil over the chili flakes and sesame seeds (discard the steeped spice mixture). This will bubble up so be careful.
Cool to room temperature and stir in the black vinegar. Carefully pour into clean jars and seal. Keep refrigerated for up to 3 months and if used often, keep at room temperature in pantry for up to 2 months.
Video
Notes
The main difference between black and green cardamom is the way they are processed. For green cardamom, the pods are harvested before maturity. Black cardamom are harvested much later and are also dried over large fires. Easily interchangeable, with the black having a more intense flavor.
You can substitute 1 tablespoon dried ground ginger or dried sand ginger, also known as ground galangal for fresh ginger.
Sichuan chili flakes are made by frying whole chilies in vegetable oil until crisp before grinding into flakes, seeds, or powder. The frying enhances the flavor, color and texture, creating a toasty flavor and characteristic vivid red color without dyes or additives. (source: The Mala Market)
You could substitute regular red chile flakes, but if you're looking for that rich, deep red color, you will need to add 2 teaspoons of paprika to the chili flakes before pouring the oil over them.
If garlic browns too quickly, remove so it doesn't burn and discard. Try to keep oil temperature around 225°F.