Yamazaki Baking's long-selling "Lunch Pack" is gaining popularity due to its ease of eating and portability. I tried a product called "UHG Sandwich Maker" that makes it easy to make similar sandwiches.
A die for bread sold by REC. Put the ingredients in two slices of bread that have been lightly warmed in the microwave, and hollow out the surroundings with a mold to make a sandwich that sticks tightly on all sides. When I tried it with egg salad, I got a sandwich that was like a hill. You can also make a cute mini sandwich by folding a piece of bread and hollowing it out.
The sandwich bread seems to change to a slightly chewy texture, probably because it is heated in the microwave or pressed with a mold. It's a nice taste for those who like a chewy texture, but those who are accustomed to fluffy bread may feel a little uncomfortable. The surface of the bread may crack when it is hollowed out, so if you do not eat it immediately, it is recommended to wrap it in a wrap to prevent it from drying out.
"UHG Sandwich Maker" is fun to see the cross section with plenty of ingredients cut in half as well as when it is completed in a pocket shape. Why don't you pack various ingredients of your choice? It is sold on various mail-order sites, and the price range is around 150-200 yen.