Cut cucumbers in half lengthwise, then slice into half-moon slices. I never peel Persian cucumbers, but if you use other cucumbers you might want to peel some of the skin off in stripes before you slice them.
Dice tomatoes or cut cherry tomatoes in half to make one cup. Only make this salad when you have flavorful fresh tomatoes.
Slice green onion to make 1/4 cup, or more if you like onion.
Peel and cut up the avocado into small cubes. Toss with lemon juice if desired, optional.
Combine the cucumber, tomato, onion, and avocado in a plastic or glass bowl and gently toss together.
Add a small amount of balsamic vinegar, enough to barely coat the veggies, and toss again.
Season to taste with your favorite sea salt and plenty of fresh-ground black pepper.
If you like it as much as I did, you probably won’t have leftovers no matter how much you make!