It's called chawanmushi. There are many videos online of foreigners being surprised by how different it is from their expectations when they try it for the first time. It's a "savory, hot egg pudding" that isn't sweet. This dish consists of a seasoned egg custard steamed with various ingredients like mushrooms, vegetables, fish paste, and fresh seafood or chicken. Often, a rare ingredient called yuri-ne (lily bulb) is also included. It’s actually a challenging dish to make, and the photo shows the chawanmushi that my skilled wife made for the first time after 35 years of marriage. She learned how difficult it was by watching my mother-in-law prepare it often. Since it looks plain, I decided to garnish it with chive flowers that I grow in a planter in the garden. In Japan, you can even find it on the menu at conveyor belt sushi restaurants.