The Komatsuna Sando (小松菜サンド) is sandwich featuring komatsuna (Japanese mustard spinach); Tokyo regional vegetable.
It sits within the Japanese Sandos family of French sandwiches — specifically the The Deli & Salad Sando cluster, which gathers the regional and stylistic variants that share its frame.
For the broader The Deli & Salad Sando tradition that frames this sandwich, see The Deli & Salad Sando.