Slice and julienne the ginger.

In a bowl, mix the julienned ginger with salt.

Prepare the pickling liquid by dissolving shiso (perilla) powder in water.

Transfer the salted ginger to a jar, pour in the red pickling liquid, seal, and shake well.

Refrigerate the jar of pickled ginger.

Pat a block of firm tofu dry with a paper towel to remove excess moisture.

Cut the white part of green onions into large, bite-sized pieces and place them in an air fryer basket.

Air fry the green onions until slightly charred.

In a heated pan with oil, pan-fry the tofu block until both sides are golden brown.

Pour a savory sauce (like teriyaki or a soy sauce/mirin mixture) over the tofu and let it glaze.

Thinly slice an onion.

In a pan, cook some of the thinly sliced beef until lightly browned.

Add dashi stock and the sliced onions to the pan, then place the remaining raw beef on top to simmer.

Assemble the bento box by placing the cooked beef and onions over a bed of rice (not pictured). Add the glazed tofu, grilled green onions, a halved hard-boiled egg, and the homemade pickled ginger.