Mix all the ingredients together in a saucepan and cook on medium heat until a thick paste forms. Continue mixing until the paste is no longer runny and has the consistency of thin mash potatoes.
Cover and let cool before using. Store covered in the fridge for up to a week or in the freezer for longer.
Notes
*Making black sesame seed powder from seeds:Toast equal amount of sesame seeds in a dry skillet until fragrant. Let cool and blitz it into a powder in a blender or in a mortar and pestle.