Place the sandwich bread in a small bowl and cover with water. Set aside to soak while you continue with the recipe.
In a large bowl, combine beef, onion, garlic, parsley, allspice, cumin, cinnamon, cardamom, salt, and pepper. Use your hands to gently toss the mixture together.
Remove the bread from the water and squeeze it to get rid of any excess water. Tear it into small pieces and add it to the meat. Add the beaten egg and again use your hands to combine the mixture until it's well mixed. Shape the meat into patties or football shapes, or shape it onto skewers and place on a baking sheet. Refrigerate overnight or for at least an hour.
To cook, preheat the grill to medium high heat or heat a cast iron skillet with a bit of oil to medium heat. Add the patties to the grill and cook for 7-8 minutes a side or until cooked through. Remove from heat.
To serve, place the patties in warmed pita bread with tabbouleh salad, sliced tomatoes, and red onion. Drizzle with tzatziki sauce.