Stick a knife in at an angle around the cabbage stem, and cut it out.
In a bowl, submerge the entire cabbage in boiling water, and let soak until it's soft enough to easily roll up the ingredients, tear off 1 leaf at a time, rinse with water, and spread out in a sieve.
Cut off the hard parts of the stems from the cooled cabbage, and finely chop.
Cut a shallow notch into the portion where you cut off the hard parts of the stem.
Prepare the filling ingredients.
Add [A], [B], [C], and the finely chopped steam into a bowl and mix together until it has become white and has clumped, and divide into 8 equal portions.
Divide the boiled cabbage leaves into 8 equal portions.
Pair up big and small leaves.
Let's roll them up .
Add one portion from step 4 on top of a small leaf.
Tuck the edges in while wrapping it up, and make a small cabbage roll.
Wrap it up in a larger leaf, and secure it with a toothpick.
Make all 8 in the same manner.
Using a pot big enough that the cabbage rolls won't stack up, add the rolls from step 8, 600ml of water, and [D], cover with a droplid, and boil over low medium heat for 30 minutes.
Add ketchup, and boil for 20 minutes while shaking the pot back and forth to coat the rolls.