Wash the tomatoes and cucumber thoroughly.
Slice the tomatoes into rounds and cucumber into half-moons.
Place the sliced vegetables in a large mixing bowl.
Add the thinly sliced red onion on top.
In a small bowl, whisk together olive oil and balsamic vinegar.
Pour the dressing over the vegetable mixture.
Season with salt and pepper to taste.
Gently toss the salad to combine all ingredients.
Let the salad sit for 5 minutes to meld flavors.
Garnish with fresh herbs before serving.