Chop the tomatoes and the cucumber. I usually take some of the seeds out of the tomatoes and put them in a colander to drain a little before mixing. You can also remove some of the seeds from cucumber if desired.
Combine all ingredients in a bowl. (Note: The amounts of the cucumber and tomato do not have to be exact. You want to have an about equal amount of each, or you can put more of one or the other to your personal liking.)
Taste for seasoning and add more olive oil, lemon juice and/or salt to taste.
Keep at room temperature until serving or refrigerate for longer storage, but know that the vegetables will release more water over time.
Serve with Salmon. To make it more substantial, I usually also add hummus and toasted pita bread.