To make the seasoning, put balsamic vinegar and sugar in a pot, bring to a boil and simmer for 5-7 minutes. Take out of the oven and allow to cool. It should have semi-thick texture.
Cut the pastrami sliced in 2 and put arugula leaves at the center, then roll up.
To assemble the brochettes, thread a pastrami roll onto a skewer, then a mini mozzarella ball, and lastly half a strawberry, with the flat side facing down.
Arrange the brochettes in a dish and add the seasoning right before serving.