Japanese Sandwich (Mixed Sando)

To Make the Tuna Salad

1. Gather the tuna salad ingredients. Then, mince ⅛ onion and soak the pieces in water for 5 minutes to remove the bitterness and astringency.
2. Squeeze the water out and add to a bowl along with ½ (5-ounce) can albacore tuna (preferably packed in olive oil), well drained.
3. Add 2 Tbsp Japanese Kewpie mayonnaise, Diamond Crystal kosher salt, and freshly ground black pepper. Mix with a fork. Flake the tuna chunks into smaller pieces and incorporate the seasonings well. Set aside. You can cover it and store in the refrigerator while you make the egg salad.

To Make the Egg Salad

1. Gather the egg salad ingredients. This recipe makes enough filling for two Tamago Sando. You can store the leftover egg salad in an airtight container for up to 2 days in the refrigerator. Put 3 large large eggs (50 g each w/o shell) in a medium saucepan and add enough water to cover by one inch (2.5 cm). Bring it to a boil on medium heat. Once boiling, cook for 12 minutes.
2. Once it’s finished cooking, transfer the eggs to iced water to stop the cooking. Let them cool completely and peel the eggshells.
3. Transfer the peeled eggs to a bowl and mash with a fork. Try to mash the egg whites into small, same-sized pieces.
4. Add ¼ tsp sugar and ¼ tsp Diamond Crystal kosher salt.
5. Add ⅛ tsp freshly ground black pepper and 2 tsp milk. Taste and add more salt and pepper if needed.
6. Add 2 Tbsp Japanese Kewpie mayonnaise and mix very well.

To Assemble the Sandwiches

1. Gather the filling ingredients for the three types of sandwiches.
2. If your bread is not pre-sliced, cut the shokupan (Japanese milk bread) into 6 thin slices, each about ⅓ to ½ inch (1 to 1.2 cm) thick. Lay out the 6 bread slices for the 3 sandwiches.
3. Using a butter knife, spread a thin layer of salted butter on all 6 slices. For the Tamago Sando, scoop the egg salad onto 1 of the slices and spread to distribute evenly.
4. For the Ham and Cheese Sando, spread Japanese Kewpie mayonnaise (and mustard, if desired) onto 2 of the buttered slices. On 1 of those slices, layer 2 leaves iceberg lettuce, 2 slices ham, 2 slices Swiss cheese, and 6 slices Japanese or Persian cucumber on top.
5. For the Tuna Sando, scoop the tuna salad onto 1 of the remaining sandwich slices and spread evenly. Put the other slice of bread on top, buttered side down. For the Ham and Cheese Sando, put the slice on top that has both the butter and mayonnaise, spread side down. Finally, put the remaining slice of bread on top of the egg salad, buttered side down. Then, place plates on top of the sandwiches to compress the ingredients slightly. Set aside for 5 minutes.
6. After 5 minutes, remove the plates. If you‘d like, cut the crusts off the sandwiches. Tip: Don't throw away the crusts and repurpose them to make Shokupan Crust Rusks. These crunchy, buttery snacks are so delicious! You can make them now or freeze those crust strips and make them later.
7. Cut each sandwich horizontally into thirds for three equal rectangular pieces. They‘re now ready to serve. For each serving, arrange one piece of each type of sandwich onto a plate for a total of three pieces. In the photo to the right, I show how to present two servings in a carry-out box.

To Store

1. You can keep any leftovers in an airtight container and store them in the refrigerator for up to 24 hours.