If you are planning to use a balsamic vinegar reduction, you can start by adding about 1/2 cup of balsamic vinegar in a small saucepan over low heat. Boil the vinegar until it’s reduced to a thick glaze, while you assemble the skewers.
Take a skewer and thread through a tomato, basil leaf, mozzarella ball, a piece of salami folded in half, then in thirds, black olive, roasted red pepper, another mozzarella ball, another basil leaf, another piece of salami and finish with a green olive.
Repeat the process for the remaining 9 skewers, then set them on a platter and serve.
Optional: drizzle the balsamic vinegar reduction over the top and serve. Alternatively, you could drizzle with homemade pesto or plain extra virgin olive oil instead.