Pickled Egg Salad Crostini with Serrano Ham

Name: Pickled Egg Salad Crostini with Serrano Ham
Ingredients: 1/2 cup apple cider vinegar; 1/2 cup distilled white vinegar; 1 teaspoon sugar; 1 1/2 teaspoons kosher salt, plus more; 6 large eggs; 1/3 cup mayonnaise; 1/4 cup finely chopped fresh chives; 2 tablespoons finely chopped fresh parsley; Freshly ground black pepper; 12 1/4-thick slices 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