This dish really says summer to me. This dish is really refreshing on a warm summer's evening. The farmer's market has an amazing array of beautiful heirloom tomatoes. Don't be shy to try something different.
Chop or slice fresh tomatoes. I use a variety of colours - red, yellow, orange. Thinly slice red onion into approximately 1" long slices.
Make a dressing with 2 parts olive oil to 1 part balsamic or red wine vinegar. I'll sometimes add a little dijon mustard for a little kick.
Gently toss tomatoes with the vinaigrette. Add freshly ground salt and pepper. If desired, add some freshly picked basil, broken into small pieces.
Sprinkle with feta cheese and serve.
Serving suggestion: serve alongside grilled salmon or chicken breasts.