The oil in the pot is about 70% hot. Add the fish pieces and fry them thoroughly.
Slice onion and ginger. Leave oil in the pot, put pepper and Pixian watercress in the pot, stir-fry until fragrant. Add a proper amount of water, various spices, onion, ginger, sugar and soy sauce to the pot, and boil it over high fire for later use.
Pressure cooker, minced onion and ginger are laid on the bottom of the pot, and the fried fish segments are staggered into the pot, leaving a blank in the middle.
Pour the cooked soup into the pressure cooker and simmer for 25 to 30 minutes. Boil it, let it cool, and take it out to eat.