Pickled Egg Salad Crostini with Serrano Ham

Name: Pickled Egg Salad Crostini with Serrano Ham
Ingredients: ½ cup apple cider vinegar; ½ cup distilled white vinegar; 1 teaspoon sugar; 1½ teaspoons kosher salt, plus more; 6 large eggs; ⅓ cup mayonnaise; ¼ cup finely chopped fresh chives; 2 tablespoons finely chopped fresh parsley; Freshly ground black pepper; 12 slices ¼”-thick country-style bread or ciabatta; 3 tablespoons olive oil; 2 garlic cloves; Chervil or parsley leaves with tender stems (for serving); 12 slices Serrano ham or prosciutto