According to the extra manga pages in Jujutsu Kaisen, a favorite food of Fushiguro Megumi is “something that matches ginger.” Also, what he dislikes is “paprika” and “side dishes that taste sweet.”

Something that matches ginger?
We frequently eat gingers, but it’s not as the main food but as a spice for various Japanese dishes. When it comes to a dish cooked with ginger, I come up with SHOGAYAKI first. It’s a Japanese meal made with grilled pork, soy sauce, and ginger. This is one of the most popular and common home cooking in Japan.

Ginger is called SHOGA in Japanese. Here’s the picture of Shogayaki!

At the Jujutsu Kaisen collaboration cafe held in Japan, Shogayaki was served as a special menu featuring Fushiguro Megumi. So it’s no doubt that Megumi loves it!

Note: the pork is colored in black with something (maybe black sesame or squid ink) to express a black Gyokuken (divine dog).
Do you remember the members of Tokyo Metropolitan Curse Technical College ate something together in Juju Sanpo from the anime episode 13? They were having a Japanese-style hot pot dish called NABE, and ginger paste is the secret to making it so delicious. Megumi learned the recipe from Itadori Yuji and cooked this hot pot!
Related Reading about Megumi
Who Is Fushiguro Megumi’s Mom? What Happened to Her?
The Meaning of FUSHIGURO MEGUMI. Is It a Girl’s Name?

How Did You Like It?