Prepare the crispy pita bread. Cut the Lebanese pita bread into medium-sized squares and toast them in the oven until golden and crispy. For a crunchier texture and richer flavor, you can fry the pita squares in oil instead.
Prepare the vegetables. Slice the cucumbers, onion, and radishes; dice the tomatoes and green bell pepper; and finely chop the parsley. Shred the lettuce, green cabbage, and red cabbage, and use only the mint leaves. Place all the prepared vegetables, along with the purslane leaves, in a large salad bowl.
Make the fattoush dressing. Add the crushed garlic, extra virgin olive oil, freshly squeezed lemon juice, pomegranate molasses, sumac, and salt. Toss well to coat the vegetables evenly with the tangy dressing.
Add the crispy pita bread and serve. Toss in the toasted or fried pita bread just before serving to preserve its crunch. Serve immediately and enjoy your authentic Lebanese fattoush!