Preheat the oven to 190°C / 375°F.
Split each pitta into two rounds and toast on a baking sheet in the middle of the oven until golden brown, about 10 minutes. Allow pittas to cool and break into bite-sized pieces. Set aside.
In a small bowl, whisk together the lemon juice, zest, salt and pepper. Add the oil and whisk to incorporate. Toss the lettuce, parsley, scallions, mint, cucumber, and tomatoes together in a large bowl.
Right before serving, add the pitta and dressing to the salad. Toss well to coat.