California Avocado Salad Flatbread Sandwich - California Avocados

Ingredients

• 3/4 cup white wine vinegar, divided
• 1/2 Tbsp. Fresh garlic, finely chopped
• 1/2 tsp. Salt and freshly ground black pepper
• 1 cup olive oil
• 2 cups Sweet onion, chopped
• 2 cups Diced tomato, chopped
• Flatbread, such as pita, 24 rounds, about 7-inch diameter
• As needed Hearts of romaine leaves
• 12 oz. Shaved Romano cheese*
• 6 California Avocados
• As needed * Jack or Fontina cheese in 1-ounce slices may be substituted