Drain and rinse the chickpeas well.
Let them sit in a colander for a minute so extra water drips off.
Dice the cucumber into bite-size pieces.
Halve the cherry tomatoes.
Finely chop the red onion and parsley.
In a large bowl, whisk together the olive oil, lemon juice, red wine vinegar, oregano, garlic, salt, and pepper.
Add the chickpeas, cucumber, tomatoes, onion, and parsley.
Toss gently until everything is coated.
Fold in the feta last.
Chill the salad for 15 to 20 minutes before serving, if you have time.