Step 1
Toss cucumber and salt in a colander set in the sink; let drain for 15 minutes. Spread the cucumber onto paper towels and pat dry.
Step 2
In a large bowl, whisk together the oil, vinegar, sugar, and black pepper. Add the cucumbers, chiles, bell pepper, onion, feta (if using), and the basil, and toss to coat. Set aside for 30 minutes before serving at room temperature.