Drain and rinse the soaked chickpeas. In a food processor, combine chickpeas, onion, garlic, parsley, cumin, coriander, baking powder, salt, and pepper. Pulse until a coarse mixture forms.

Transfer the mixture to a bowl and stir in flour. Refrigerate for 30 minutes.

Heat oil in a frying pan over medium heat. Form the mixture into small balls and fry until golden brown on all sides, about 5-7 minutes. Drain on paper towels.

Take a pita half and fill it with shredded lettuce, diced tomato, and sliced cucumber.

Add 3-4 falafel balls into each pita half.

Drizzle with tahini sauce and serve immediately.