Preheat oven to 375°F and line a baking sheet with parchment paper.
Prepare falafel: Place garlic in a food processor and pulse to chop. Add onion and pulse to chop. Add soaked chickpeas, parsley, cilantro, oil, cumin, Za’atar, coriander, cayenne and salt. Process until smooth, stopping to scrape down sides of bowl as needed.
Take 2 to 3 tbsp of mixture, roll it into a ball and then pat it flat; place on prepared baking sheet. Repeat with remaining mixture. Bake for about 25 minutes, flipping halfway through, until golden.
Meanwhile, make dressing: In a small bowl, combine tahini, lemon juice, oil and ¼ cup water, or as needed, adding water a bit at a time to get desired consistency. Season with salt.
To a large bowl or platter, add lettuce. Top with falafel patties, cabbage, cucumber and tomatoes. Drizzle dressing over top or serve alongside.