In 3.5qt pot over medium heat; bring vinegar, sugar and salt to a simmer. Reduce heat to medium/low and continue to gently simmer for approximately 15-20 minutes or until mixture decreases by almost half and becomes syrupy. Whisk occasionaly while cooking, especially the last 5 minutes. Transfer balsamic glaze to clean, airtight container and refrigerate to cool. Glaze will thicken as it cools. If your glaze thickens too much, whisk in a splash of balsamic vinegar until desired consistency. Store in refrigerator and use within 1 week. Yields: approximately 1 cup.

Preheat oven to 400°F

Cut sourdough slices in half, brush both sides with olive oil and transfer to baking sheet.

Bake for 5-6 minutes, flip slices and bake for 5-6 more minutes or until golden brown.

Remove bread from oven and immediately top with cheese, tomato, prosciutto, basil, pistachios, balsamic glaze and sea salt.