Cucumber, Potato, and Green Bean Salad - Lidia

Ingredients

• 1 teaspoon kosher salt, plus more for the pot
• 3 large red potatoes, cut into 1½-inch chunks (about 1¼ pounds)
• 1 pound green beans, trimmed
• 3 tablespoons red wine vinegar
• ⅓ cup extra-virgin olive oil
• Freshly ground black pepper
• 1 English cucumber, sliced into ¼-inch-thick half-moons
• ½ medium red onion, thinly sliced