Slice the tomatoes and cucumber.

Chop the green onion.

In a serving bowl, layer half of the tomato slices.

Add all of the cucumber slices over the tomato layer.

Layer the remaining tomato slices on top of the cucumber.

Sprinkle the chopped green onion over the tomatoes.

In a jar with a tight-fitting lid, combine the Italian salad dressing, vinegar, basil, salt, pepper, and garlic salt.

Shake the jar well to combine all ingredients.

Pour the dressing over the salad.

Cover the bowl and chill in the refrigerator for at least 25 minutes before serving.