Lemony Chickpea Salad

Name: Lemony Chickpea Salad
Ingredients: 2 tablespoons pure olive oil; 1 yellow onion, quartered; 2 carrots, halved; 1 celery rib, halved crosswise, plus 4 small celery ribs, finely diced; 1 pound dried chickpeas, soaked overnight and drained; 4 rosemary sprigs and 4 thyme sprigs, tied together with string; Kosher salt and freshly ground pepper; 1 medium red onion, finely chopped; 1/2 cup red wine vinegar; Finely shredded zest and juice of 1 lemon; 2 garlic cloves, very finely chopped; 1 teaspoon finely chopped rosemary; 1/2 teaspoon dried oregano; 1 1/2 teaspoons finely chopped peperoncini; 1 cup extra-virgin olive oil; 3/4 cup finely chopped flat-leaf parsley