Toss bread with olive oil, salt, and pepper.
Bake on a sheet pan at 400°F for 8–10 minutes, tossing halfway.
In a bowl, mix cucumber, tomatoes, radishes, green onions, red onion, feta, and olives.
Add toasted bread.
Whisk vinaigrette ingredients and pour over the salad.
Toss gently and let sit for 20–30 minutes before serving.
