Preheat the oven to 350˚F.
Brush the pita with oil, sprinkle with salt and bake on a baking sheet for 10-12 minutes, until deep golden and toasted.
Let cool, then break apart into chunks.
Arrange the lettuce, cucumber, tomatoes, purple onion and cilantro in a shallow bowl or on a platter.
To make the dressing, whisk all the ingredients in a small bowl or shake them in a jar.
Drizzle over the salad and serve immediately, passing extra dressing at the table.