These were quite tasty.  And far more filling than I think either of us had been expecting.  But light in the stomach, unlike some of your meat and cheese heavy sandwiches.  This was experimental and may become a staple.

2 T mayo (depending on how many sandwiches.  This seemed to do three)

1/2 tsp wasabi (I’d suggest more, or letting it sit for a bit for the wasabi to settle in.  Last set of sandwiches we used 1 1/2 tsp)

8 thin slices sandwich bread

1 medium cucumer, peeled, seeded, thinly sliced (I didn’t seed)

1 c chopped watercress (or whatever looks right to you, works just fine as leaves and stems, too)

Combine mayo and wasabi

Thinly spread on bread.  Top with cucumber and watercress.  Sprinkle with salt and pepper.  Close.  Slice.  Serve.