Combine tomatoes, parsley and red onion in a bowl.
Whisk together the lemon juice and olive oil or shake them in a lidded mason jar.
Pour the dressing over the salad and toss to combine. Taste and season with salt and pepper.
This salad is wonderful with fresh summer tomatoes, however you can make it year round with Roma or cherry tomatoes from the grocery store. Can substitute Quick Pickled Onions for the red onions for even more flavor.