Rinse 2.5 cups of rice (short grain rice or medium grain rice, e.g. sushi rice, 535 grams / 1.17 pounds) until the water drains clear. Put the rice in a medium sized bowl and fill the bowl with some water. Soak it overnight or for 12 hours.
Strain the water away and air dry the rice for 1 hour. (The weight of the rice will increase to roughly 697 grams / 1.53 pounds.)
Grind the rice finely in a powerful food processor until the rice turns into fine powder. (You will have to stop and move around the rice flour with a scraper as it grinds. Otherwise, some rice flour and particles will stick to the wall of the processor and won’t get ground. The whole grinding process will take about 6 mins.
Sift the rice flour into a clean bowl in two or three lots. (It sifts better when you do it in smaller quantities.) Remove any clumps or unground rice grains. When the rice flour is sifted once, sift it one more time. If you ended up with too much unground rice grains, put them back into the food processor and grind them again until you get the fine rice flour. This should result in about 4.5 cups of rice flour.
HOW TO MAKE RICE CAKE WITH A MICROWAVE
Combine rice flour, cornstarch, fine salt and 1/4 cups of boiling water in a microwave safe bowl. Mix them well. Add another 1/4 cups of boiling water and mix them again. (The rice cake mixture should be smooth and easy to stir, not hard like cookie dough.)
Cover the bowl with cling wrap, leaving a little gap for steam to escape. Put the bowl into a microwave and heat it up for about 2 minutes (based on 1250W microwave).
Take the bowl out and add 1/4 cups of the remaining boiling water. Cover the bowl again and return the bowl to the microwave and heat it up for a further 1 minute and 30 seconds. Remove the bowl from the microwave.
Cover the cutting board with a silicone baking mat or a few layers of cling wrap to prevent rice cake sticking onto it while shaping the rice cake. Carefully remove the rice cake dough from the bowl and place it on the mat.
Put a pair of thick cotton gloves (layer 1) and food safe gloves (layer 2) on top on your hands. (This is because rice cake dough will be very hot to touch.). Knead the rice cake dough. Pound it with a pestle for about 5 mins to give the rice cake a nice elastic texture.
HOW TO MAKE RICE CAKE WITH A STEAMER
Combine rice flour, cornstarch, fine salt and 2/3 cups of boiling water in a bowl. Mix them well.
Cover the steamer with baking paper or a clean tea towel and place the rice flour mixture on top. Close the lid and steam it for 20 minutes over high heat.
Cover the cutting board with a silicone baking mat or a few layers of cling wrap to prevent rice cake sticking onto it while shaping the rice cake. Carefully place the steamed rice cake dough on the mat.
Put a pair of thick cotton gloves (layer 1) and food safe gloves (layer 2) on top on your hands. (This is because rice cake dough will be very hot to touch.). Knead the rice cake dough. Pound it with a pestle for about 5 mins to give the rice cake a nice elastic texture.
PREPARE RICE CAKE FOR TTEOKBOKKI (SPICY RICE CAKE)
Divide the rice cake dough evenly into 5 pieces.
Drop the 1/2 tsp of sesame oil on to your palm and gently rub onto the rice cakes.
Roll the rice cake into 1 – 1.5 cm /0.4 – 0.6 inch diameter cylinder shaped rice cake and cut both ends.
Cut the main part of the rice cake into 6 cm/4 inch long pieces (about little finger size). Now you have the rice cake ready to use in tteokbokki or other stir fry dishes.
PREPARE RICE CAKE FOR TTEOKGUK (KOREAN RICE CAKE SOUP)
Divide the rice cake dough evenly into 2 pieces.
Drop the 1/2 tsp of sesame oil on to your palm and gently rub onto the rice cakes.
Roll the rice cake into 2 – 3 cm/0.8 – 1.2 inch diameter cylinder shaped rice cakes.
Place the rice cakes on a large plate and cover with cling wrap. Refrigerate it for about 1 hour to harden it for easier slicing. However, if you are in a rush, you can still slice the rice cake soon after shaping it.
Slice thinly (about 0.5 cm / 0.2 inch thickness) and diagonally like oval shapes. Now you have the rice cake ready to use in your rice cake soup.
Notes
1 Tbsp = 15 ml, 1 cup = 250 ml
The amounts of water used above are based on homemade rice flour, which is wet-milled. Wet-milled rice flour is more moist than dry-milled rice flour, requiring less water for this recipe. If you are unable to find wet-milled rice flour from your grocer, I suggest you make your own following the instructions above. It's very easy to make at home!
The above ingredients will result in about 450g (1 pound) rice cake.
Cooking time above only accounts for making rice cake using a microwave. It doesn't count for making the rice flour from scratch.
Lots of helpful tips are mentioned in the main post above. Be sure to read them before you make garaetteok to increase your chance of success.