
In a medium-sized pot, combine the acorn starch with water. Stir continuously while cooking over medium heat.
As the mixture begins to thicken (it takes about 3 minutes for induction and 4 minutes 30 seconds for a gas stove), add the salt. Reduce the heat to low and continue stirring for 20 minutes.
Incorporate the perilla oil (or sesame oil) and cook for an additional 10 minutes over low heat, continuing to stir.
Transfer the acorn jelly into a container and let it cool at room temperature for 1 hour. After cooling, cover with the lid and refrigerate for at least 4 hours before using.
Combine the seasoning sauce and mix well.
Place the salad ingredients (cucumber, onion, carrot, and lettuce) in a mixing bowl. Add half of the seasoning sauce and mix well.
Add the acorn jelly and the remaining seasoning sauce. Mix carefully and lightly but thoroughly (if you mix it too hard, the acorn jelly will break.)
Serve with a bowl of rice and other Korean side dishes.