Rinse, drain and peel ginger; Slice a small part of the ginger; Grate the remaining with a microplane grater over a bowl.
Put a strainer over a bowl; Line the strainer with a piece of cheesecloth, draping the corners over the sides; Spoon the grated ginger into the center of the cheesecloth; Gather up the 4 corners and twist to squeeze the grated ginger for juice for later use.
Rinse fish steaks; Pat-dry them with kitchen paper; Remove any bones with a pair of tweezers; Slice them; Put them in a mixing bowl; Add seasoning (1) and the ginger juice from the step 2; Mix; Leave it for 30 minutes.
Rinse and drain dried goji berries.
Rinse matrimony vines under running water; Drain it; Cut off any roots; Discard any wilted leaves; Soak them in water for an hour; Remove them; Rinse them under running water again; Drain them; Separate their stems from their leaves by holding the matrimony vine with one hand and wiping the leaves out from the top to the bottom with another hand.
Rinse and drain fish backbones; Stuff them together with the matrimony vines’ stems into a food filter bag.
Fill a pot with 2.5L water; Bring to the boil over a high heat; Turn off the heat.
Add 2 tbsp oil to a anodized aluminum saucepan and swirl the pan; Add the ginger; Stir it over a high heat till fragrant; Turn to a low heat; Arrange the fish steaks into the pan; Turn to a high heat; Pan-fry the fish steaks over a high heat till both sides are lightly brown; Turn to a low heat; Add the food filter bag with the fish bones and the matrimony vines’ stems; Pour the boiling water from the step 7 into the pan; Bring to the boil over a high heat; Turn to a low heat; Cook over a low heat for 20 minutes; Remove the fish bones and the matrimony vines’ stems in the food filter bag with a pair of spring-action tongs and discard; Add most of the dried goji berries and the matrimony vines’ leaves; Bring to the boil over a high heat again; Turn to a low heat; Cook over a low heat for 20 minutes; Add all the remaining ingredients; Bring to the boil over a high heat again; Stir seasoning (2) into the soup; Turn off the heat; Arrange the soup into serving bowls; Ready to serve.