Place 3 eggs in a saucepan and cover with water. Bring to a boil over medium heat and cook for 11 minutes. Drain and drop into an ice water bath to cool. Peel.

Place eggs in a mixing bowl and mash into small pieces with a fork, then mix in 2 tbsp mayonnaise (preferably Japanese Kewpie), 1 tbsp milk, ¼ tsp sugar, ¼ tsp salt, and some freshly ground black pepper.*

Spread salted butter on one side of 2 bread slices (you can use Japanese milk bread, brioche bread, or challah bread). Spread the filling on one slice and place the other bread slice, buttered side down, on top. Press slightly to seal. Repeat.

Makes 2 sandwiches.

* Optional: add 1 tsp Dijon mustard.