3 small Persian cucumbers or garden cucumbers
1 cup diced tomato or cherry tomatoes
1/4 cup thinly diagonally sliced green onion or thinly sliced sweet onion (or more)
2 tsp. fresh lemon juice (optional, for tossing with avocado)
about 1 T good-quality balsamic vinegar
sea salt and fresh ground black pepper to taste
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.) Diagonally slice green onion or slice onion to make 1/4 cup, or more if you like onion. Peel and cut up the avocado into small cubes.
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. (I used about a tablespoon of vinegar, which was plenty.) Season to taste with your favorite sea salt and plenty of fresh-ground black pepper.