Slice ginger thinly. Cut green onion lengthwise, remove the core, and slice thinly. Soak in water and drain before serving.

Place pork belly in a pressure cooker, add water and 1 tbsp sake. Cover and heat on medium until pressure builds, then cook on low for 20 minutes. Let pressure release naturally.

Separate pork belly from the boiling liquid. Rinse the pork and cut into bite-sized pieces. Wash the pressure cooker lightly.

Add pork, seasonings (☆), green onion (green parts), and ginger to the pressure cooker. Cover and heat on medium until pressure builds, then cook on low for 15 minutes. Let pressure release naturally.