Slice cucumber

half the tomatoes

mix with corn

 In a bowl, mash avocado with lemon or lime (both are great and keep it from browning with a little flavor), add the oil and vinegar and pepper. 

I always hate it when people say "add to taste" in recipes, but the red wine vinegar is really to taste, or you can omit it altogether. It's just to add a kick and make the avocado a bit runnier like a dressing. 

The balsamic lends the flavor to taste like a caprice salad, which I love.