I never measure this, so quantities are approximate. I use the slicer attachment to the Kitchenaid mixer, or the food processor, but you could use the slicing side of a box grater.
1 seedless cucumber peeled and sliced thin (Chinese cucumber. They are a little firmer and have fewer seeds)
1⁄2 red onion sliced thin
salt & pepper
1 teaspoon dried dill
1⁄4 cup cider vinegar
1 small container (8 ounces) sour cream
1/2 cup mayo
Cover cucumber and onion with ice water and chill for at least 2 hours.
Make a dressing of vinegar, sour cream, mayo, salt and pepper and dill. Add to drained cucumber and onion. Taste and adjust seasoning. Serve within an hour or so or the cucumber and onion will start to get limp.