To make a chilled cucumber and onion salad, dissolve 1 tablespoon of sugar in 3 tablespoons of vinegar, and add 1/4 teaspoon each of salt and pepper. Thinly slice 2 medium cucumbers and 1 small red onion. You can use a mandolin or the thin-slice attachment of a food processor to make this easier. Arrange the cucumbers and onions in a sealable container, and cover with vinegar mixture. Refrigerate for one to two hours before serving.
Add some variety to this salad by adding 3 tablespoons of fresh dill weed to the vinegar mixture. You can also use mint, basil, tarragon and cilantro. To make a sweet and creamy salad, use a small sweet onion and add 1/2 cup of sour cream to the vinegar mixture. This makes a larger amount of dressing, so use double the number of cucumbers.
Another variation uses tomatoes. Seed and dice 1 cucumber and 1 tomato. Toss the sliced and diced vegetables together with 1/2 cup diced red onion. Mix 1/2 cup olive oil with 1/2 cup red wine vinegar, and add 1 teaspoon each of salt and pepper. Pour the mixture over the diced vegetables, and chill before serving. Add finely chopped fresh herbs such as marjoram, basil or parsley, or mix in some rinsed and diced olives or capers.