Here is a picture of our dinner last night, thanks to my daughter sharing her variation on this salad. Very low calorie, but delicious. I added a little sugar to the dressing to take the "bite" out of the vinegar. An old trick that my grandmother taught me whenever using acidic ingredients. We had grilled chicken, but you could add just about anything you like, such as shrimp, or just veggie.
Green beans - steamed (about 5 minutes, then rinse in cold water)
Small red potatoes - steamed (left to cool)
3 TBL olive oil
3 TBL apple cider vinegar
1 tsp Dijon mustard
1 tsp garlic - minced
1/2 tsp sugar
salt & pepper to taste (although my daughter hates that I eat too much salt, so this is my addition)
Easy, cool for summer, and very nutritious.