Greek Dinner Salad

Name: Greek Dinner Salad
Ingredients: 1/2 small red onion, thinly sliced; 2 tablespoons red wine vinegar; 1 cup pepperoncini and/or kalamata olives, plus 1 tablespoon brine from the jar; 1 small clove garlic, minced; Kosher salt and freshly ground pepper; 1/3 cup extra-virgin olive oil; 2 romaine lettuce hearts, thinly sliced crosswise; 1 cup mixed fresh herbs (parsley, dill, mint and/or oregano); 1 pint cherry tomatoes, halved; 2 large cucumbers, peeled, seeded and cut into chunks; 1 cup crumbled feta cheese; 12 stuffed grape leaves (from the deli counter)