In a large bowl, add the chicken which has been cut into small pieces.
Then add the olive oil, yogurt, parsley, garlic, lemon juice, paprika, cumin, salt, allspice, oregano, ginger, black pepper, and cayenne powder.
Mix all together to marinade evenly.
Cover and let it sit in the fridge for at least an hour or overnight if you have time. Otherwise, just half an hour or immediately.
If you don't want the wooden skewers to burn in the oven, soak them in warm water for about 20 minutes.
Preheat your BBQ/grill.
Thread the pieces of chicken onto the skewer along with the bell peppers and red onion. Once the skewer is full, repeat with the other skewers until all the chicken is threaded.
Grease your grill and add the skewers.
Roast on each side for 5 to 6 minutes until it has some nice BBQ marks all around. Make sure the chicken has cooked through in the center, about 15 to 20 minutes and then take off the grill.
Garnish with more parsley and a sprinkle of sumac. Serve warm.