Put adzuki beans in a pot and cover them with water. Bring to boil. After it comes to boil, reduce heat to low to medium and boil for 2 minutes.
Pour beans into a colander to drain water. Rinse beans well.
Put beans in a pressure cooker and add approximately three times of water. Cover it with aluminum foil and cook for 12 to 15 minutes after pressure is developed. If a pressure cooker is not used, cook beans until they are soft.
Remove pressure cook from the heat and wait until the pressure is gone
Pour beans in a pot with the cooking water and add pitted dates
Stir occasionally and reduce to loose paste consistency. Don't reduce it too much as it gets thicken when cooled.
Recipe by Asian Vegan & Beyond at http://www.asianveganandbeyond.com/sweet-red-bean-paste-tsubuan/