Start by washing the mixed greens thoroughly under cold water. Remove any wilted leaves, then pat them dry using a salad spinner or paper towels.
Using a sharp knife, slice your cucumber into thin rounds. Halve the cherry tomatoes and thinly slice the red onion.
In a large bowl, combine the mixed greens, sliced cucumber, halved cherry tomatoes, and red onion. Gently toss them together to mix the ingredients well.
Sprinkle the crumbled feta cheese evenly over the salad.
Drizzle the balsamic vinaigrette over the salad and toss gently to coat all the ingredients.
Transfer the salad to a serving dish or serve directly from the mixing bowl. Enjoy this Green Salad as a light meal or a delightful side dish.