Start by washing 2-3 medium-sized cucumbers thoroughly under cold running water. You can peel them if desired, or leave the skin on for added texture and nutrients. Slice the cucumbers thinly into rounds or half-moons and place them in a large mixing bowl.
Peel and thinly slice 1 medium red onion or white onion. Red onions are often preferred for their milder flavor and vibrant color, but you can use whichever variety you prefer.
Add the sliced onions to the bowl with the cucumbers. Toss them together gently to distribute them evenly.
In a small bowl, whisk together 1/4 cup of white vinegar, 2 tablespoons of extra virgin olive oil, 1 tablespoon of honey or sugar (optional, to balance the acidity), 1/2 teaspoon of salt, and a pinch of black pepper. Adjust the sweetness and seasoning to taste.
Pour the prepared dressing over the cucumber and onion mixture in the bowl. Use a spoon or spatula to toss the salad until the vegetables are evenly coated with the dressing.
If time allows, cover the bowl with plastic wrap or transfer the salad to an airtight container and refrigerate for at least 30 minutes to allow the flavors to meld and the salad to chill.
Before serving, you can garnish the cucumber and onion salad with fresh herbs such as chopped parsley, dill, or mint for added flavor and visual appeal.
Transfer the cucumber and onion salad to a serving dish or individual plates and serve chilled as a refreshing side dish or accompaniment to grilled meats, fish, or sandwiches.