1. **Prepare the cucumbers**: Peel the cucumbers (optional) and thinly slice them. You can use a mandoline for even slices if you prefer.
2. **Mix the ingredients**: In a large bowl, combine the cucumbers, red onion, and fresh dill.
3. **Make the dressing**: In a small bowl, whisk together the vinegar, olive oil, sugar (if using), salt, and pepper until well combined.
4. **Toss the salad**: Pour the dressing over the cucumber mixture and toss everything until evenly coated.
5. **Chill and serve**: Let the salad sit in the fridge for at least 20-30 minutes before serving, allowing the flavors to meld.
Enjoy this cool, tangy salad as a side dish for grilled meats, sandwiches, or just as a light snack!
