It's not only food for the ailing, though. (I like chicken soup anytime, for example.) Many ingredients such as assorted vegetables, beef, pumpkin, abalone, shrimp are all used to make diverse variations. And on dongji, the winter solstice, we Koreans eat patjuk.
Patjuk is made from pat(red beans). As it is the day when the sun turns, in the ancient days dongji was observed with much reverence; some historians say it was even considered the true New Year's Day (seolnal). It is a day to get rid of your old debts, forget old grievances and try to start anew, a day to greet good fortune with wide open arms.
Because red is the color of the sun, eating juk made from red pat was believed to would ward off evil spirits in the following year. Traditional medicine doctors state that the nutritional reasons for eating patjuk in the winter is based on Korea's long agricultural history as well. Pat stimulates your inner organs and rids the body of toxic wastes, something that is difficult to do with lack of exercise in the "farm lazy" winter season.
Also, pat is considered a yin and the saealshim (glutinous rice balls which are added in the juk) a yang, and eating 'a yang within a yin' is supposed to be beneficial for your body in the winter months.
Patjuk comes either non-seasoned or sweet (which is called dan patjuk, in that case). I prefer the non-sweet kind, where I can taste the pat properly. The lack of salt is easily fixed by kimchi or dadaegi (mixture of various chilis, garlic, radish). Patjuk is traditionally paired with dongchimi, a cold radish kimchi soup. (Kimchi, like cheese, comes in a gazillion different varieties).
I have never made patjuk in my life; it's such a hassle to make. I usually get patjuk at my mother's or buy it. This year I got carryout at Bonjuk, the juk franchise that is all over Korea, and which was featured heavily with a fictional name in the K-drama 'Boys over Flowers'.
To be honest, patjuk is best at those traditional street markets but I live right next to a Bonjuk store and laziness won over. The juk was okay. A spoonful with saealshim and dadaegi.
The dongchimi they gave me was soooo bland. Notice how in the photo it's completely washed out? It's not supposed to look that way, so here's a photo of my mother's dongchimi, complete with flower carrots. Yum!