Heat a large non-stick skillet on medium low heat. If you don't have a non-stick skillet, add 2 teaspoons of oil to the skillet.
Cut the zucchini in half lengthwise, then cut each half lengthwise. Cut each piece crosswise into ½-inch thick pieces.
Carefully place the zucchini into the skillet so that the oil doesn't splatter. Arrange the pieces into one layer and let it cook and brown for 3 to 4 minutes without stirring.
Meanwhile, cut the tomatoes in half lengthwise.
Stir the zucchini and add in the tomatoes. Cook for 1 to 2 minutes.
Carefully add in the balsamic vinegar and let it cook for 30 seconds to thicken to a glaze. Stir the vegetables to coat them in the glaze.
Salt and pepper the vegetables if desired. Remove from the stove and serve.