1Peel (optional) cucumbers and slice about 1/4 inch thick. Cut and seed tomatos. Peel and slice red onion.
2Put all vegetables into a bowl, pour vinegar and water over the vegetables. Water is approximate - you need enough to ensure all vegetables are covered. I use enough vinegar to ensure a very tart flavor - again amounts are approximate.
3Add salt and pepper. Cover and refrigerate for several hours before serving - allows flavors to develop well.