Few things are more refreshing than this light, crunchy dish. Letting the onions sit in vinegar before assembling adds a tart, almost-pickled flavor that brightens the whole salad. Serve it as a side to... perk up Basic Poached Salmon, or pair it with a spicer dish to provide some cooling relief to your tastebuds.
In a medium bowl, mix together the vinegar and onions. Let sit for 1 hour.
Cut the cucumber into quarters lengthwise and remove the seeds. Then slice the cucumbers about ¼-inch thick. Sprinkle the cucumber with salt and add to the onions. Mix in the chopped dill. Chill for 30 minutes, then serve.