Red or Green Mustard Spring Rolls

Oddly enough, Japanese red mustard leaves wrapped around Vietnamese spring roll filling wind up looking like Middle Eastern stuffed grape leaves! Southern curled mustard works equally well, provided the leaves are large. Both types make dandy wrappers, but first must be blanched to become more mellow (although still peppery and bitter) and malleable. Thus transformed, the forgiving “crêpes” can be rerolled, patched, and otherwise handled in ways that dough doesn’t permit (but keep some blan