Balsamic reduction preparation:

Put the balsamic vinegar in a saucepan or small saucepan and cook over medium heat until the vinegar has been reduced by at least half (it will take about 30 minutes for an amount of about 500 ml of vinegar that will be reduced to about 250 ml). For a concentrated, but still liquid balsamic reduction, cook to this point. For a thicker sauce cook until everything is reduced to about 125 ml (that is, a quarter of the original volume).
When the balsamic vinegar reduction is the thickness and concentration that you like, remove it from the heat and let it cool down. Store the reduction or balsamic sauce in a container with a lid or in a bottle and use it as you like.

Preparation of the capresse salad:
Now cut the tomatoes into slices, as well as the mozzarella.

In a plate put, alternating them, a tomato slice and a cheese slice. When you have it add a little salt and oil to the set.

Finally, water it lightly with the balsamic reduction and pesto.