Place the sliced cucumber and red onion in a large bowl. Then combine the vinegar, maple syrup, and dill in a small bowl and mix well. Pour the dressing over the salad and stir to evenly coat the slices.
Refrigerate for 1 hour or longer to chill and then serve.
Notes
For the best flavour and texture, plan to make this salad not more than 1-2 hours before serving, as it softens more and more as it sits in the vinegar.For a creamy dressing, add 2 tablespoons of dairy-free yogurt or cashew cream.