At Jongno Stew Village, a popular lunch spot in the Dobong district of northern Seoul, pollock stew and kimchi jjigae are the best sellers. But no matter the order, Lee Hae-yeon, the owner, serves small side dishes of kimchi, tofu, boiled bean sprouts and marinated perilla leaves.

Customers can help themselves to more, and “people are going to take more than they’re going to eat,” Mr. Lee said. “Koreans like to err on the side of abundance when it comes to food.”

Mr. Lee pays a price for that: about 2,800 won, a little over $2, for every 20 liters of food he throws out. All day, leftovers go into a bucket in the kitchen, and at closing time Mr. Lee empties it into a designated bin outside. On the lid, he attaches a sticker purchased from the district — evidence that he’s paid for the disposal.