Spread the beef out on a cutting board and roll the green beans up. Once rolled up, lightly sprinkle with salt. Use a tea strainer to lightly dust with flour.

Heat the oil in a frying pan and put the end of the roll on the pan to cook. First, cook on high heat until browned, then lower the heat to low and continue to cook.

Once cooked, add the ★ ingredients and coat the rolls over high heat. Cut in half and add to your bento. Sprinkle some white sesame seeds.

Unagi Sauce. It's a bit sweet, so add some sake or water if you prefer.

https://cookpad.wasmer.app/us/recipes/143329-basic-tare-sauce-for-eel

The top picture shows a thick rolled omelet which can be found at"Thick Tamagoyaki with Just 1 Egg for Bento"

https://cookpad.wasmer.app/us/recipes/143395-thick-tamagoyaki-with-just-1-egg