In a large bowl, combine 10 chopped romaine lettuce leaves, 4 chopped tomatoes, 1 large sliced cucumber, 1 sliced onion, and 1/2 cup chopped parsley.
Season the salad with 1 tablespoon of salt and mix well.
Drizzle 2 tablespoons of lemon juice and 1 tablespoon of extra virgin olive oil over the salad.
Gently stir the salad to evenly distribute the lemon juice and olive oil.
Add 1 cup of sour cream to the salad.
Mix the salad until all ingredients are evenly coated with the sour cream.