Boil water and pour into a bowl. Add gelatin and sugar, dissolve well. (You can use hot water from an electric tea kettle as well.)
Add the black sesame seed paste to the bowl from Step 1, and stir the mixture carefully.
Pour cold milk into the bowl from Step 2, stir well, and pour the mixture into small cups. Refrigerate for 1- 2 hours.
I have tried store-bought paste, homemade paste, etc., but I recommend this black sesame seeds paste, since the paste does not float to the top or sink to the bottom of the pudding.
Story Behind this Recipe
I bought a jar of black sesame seed paste and used it for goma-ae (vegetables with sesame seeds sauce), but there was still some left. I wanted create a rich and milky black sesame seeds pudding and came up with this recipe. It turned out to be very delicious.
I recommend you use gelatin which dissolves in hot water. (Not the type which needs to be soaked in water). Be sure to dissolve the gelatin in hot water. If you add gelatin to cold water and boil the mixture, it won't harden. Either use boiling water and set aside in a bowl, or use hot water from an electric tea kettle, and the water temperature will be just right.