Place the frozen crabs in a large bowl of water to thaw slightly and wash them.

Using a kitchen brush, scrub the crabs thoroughly all over to clean them.

After cleaning, drain the water and place the crabs in a clean bowl.

Using the back of a knife, carefully break off the sharp tips of the pincers to prevent getting pinched.

Remove the apron (the flap on the underside) of each crab.

Open the top shell by pulling it away from the body.

Remove and discard the gills from both sides of the crab body.

Cut the crab body in half with a knife.

Use kitchen scissors to cut the smaller legs into bite-sized pieces, trimming off the pointy ends.

Scoop out the tomalley and roe from the top shells into a separate small bowl.

Rinse the collected tomalley and roe through a strainer to clean them.

Give the cleaned crab pieces a final rinse in clean water and drain them well.

Weigh out approximately 2 pounds (about 900g) of the cleaned crab for the recipe.

Crack the larger claws with the back of a knife so the seasoning can penetrate easily.

In a large mixing bowl, add the cleaned crab pieces and the strained tomalley and roe.

Finely mince the garlic and ginger.

Add the minced garlic and ginger to the bowl with the crab.

Add the Korean hot pepper flakes (gochugaru).

Pour in the soy sauce.

Add the sugar.

Mix everything thoroughly with a spatula until the sugar is dissolved and the crab is evenly coated.

Crush toasted sesame seeds in your hands and add them to the mixture.

Give it a final gentle mix.

Transfer the seasoned crab to an airtight container.

Close the container and refrigerate. It's ready to eat but tastes best the next day.