• Preheat the oven to 500°F (if using a baking sheet) or as high as it will go (if using a baking stone/steel; place the stone in the top third or place the steel in the bottom third of the oven before you start preheating). Let the oven preheat for at least 30 minutes. Then, if you’re using a baking stone or steel, switch the oven to Broil on high.

To make the balsamic glaze

• Pour the balsamic vinegar into a small saucepan. Bring it to a boil over high heat, then reduce the heat to medium-low and simmer for 6 to 8 minutes, until it thickens enough to fully coat the back of a metal spoon. Do not let the vinegar cook too long, since it thickens more as it sits; if it gets too thick, you won't be able to drizzle it on the finished pizza.
• As soon as the balsamic glaze is finished, use a rubber spatula to scrape it into a small heatproof ramekin. You will have about ¼ cup.

To assemble and bake the pizza

• Stretch or roll out your dough to a 12- to 14-inch circle, then transfer it to a baking sheet / pizza pan or a lightly floured pizza peel (if using a baking stone/steel).
• Prick the dough all over with a fork and brush it with a thin coating of olive oil, making sure you get all the way to the edges. Season with a big pinch of salt, a few grinds of pepper, and a pinch or two of Italian seasoning.
• Tear the prosciutto into smaller pieces and scatter them evenly across the dough. Top with the sliced roasted red peppers and diced mozzarella, then season with another big pinch of salt and a few grinds of pepper.
• Transfer the pizza to the oven and bake until the crust is golden and the cheese has browned in spots—8 to 10 minutes on the baking sheet, 5 to 8 minutes on the baking stone/steel.
• Take the pizza out of the oven, and immediately drizzle it with about half of the balsamic glaze. (Save the remaining glaze to serve over ice cream later!) Sprinkle the chopped chives over top, slice, and serve.