In the Kanto region, strong soy sauce was used as seasoning even for shiru-mono dishes (soup dishes) and nimono (boiled and seasoned foods) so that the tastes of these dishes could be enjoyed even when they became cold, and dishes using such seasoning developed as souvenir dishes, for example, in the form of box lunches.
関東では汁物や煮物にも濃口醤油を利用し、冷めても味を損じない濃い味付けが行われ、折り詰などの土産料理として発達した。