To make the Balsamic Glaze:

1. In a small saucepan, bring the balsamic vinegar and brown sugar or honey to a simmer. Cook over low heat, stirring occasionally, until reduced by half, about 30 minutes. Allow to cool, then store in an airtight container in the refrigerator. (Glaze will thicken a bit more as it cools.)

Assemble the salad:

1. Arrange greens, tomatoes, and mozarella as you would like. Slicing and layering the tomatoes and mozzarella make it pretty, but also makes it easy to get even amounts of each ingredient in every bite.
2. Drizzle with olive oil and balsamic glaze. Season with freshly ground sea salt to taste.