While the bulgur is soaking, whisk together the lemon juice and olive oil. Stir in the mint, pepper, cinnamon, salt, allspice, and nutmeg.
When it has cooled, transfer the bulgur wheat to a large bowl; add the remaining filling ingredients and toss. Whisk the lemon juice mixture, add it to the bulgur wheat, and toss again. Taste and adjust the seasoning. Refrigerate in a covered container for at least 1 hour before serving.
To assemble each sandwich, split open a pita half and spread the inside with 2 tablespoons of the Hummus, insert a romaine leaf, and fill with ½ cup of the Tabbouleh.
In separate covered containers in the refrigerator, the Hummus will keep for up to 5 days, and the Tabbouleh will keep for up to 3 days. Assemble the sandwiches just before serving.