First, get a bowl and add all the spices along with the yogurt.

Add the sliced chicken breast to the bowl and mix well to coat.

After mixing the chicken with the marinade, heat a pan on the stove and add 1 tablespoon of oil with the beef fat (or butter).

Once the oil is hot, add the marinated chicken and sear it.

After the chicken absorbs the fat and oil, remove it from the pan.

Next, add the bell peppers and tomato to the pan.

Stir well, then return the chicken to the pan and cook for 5 minutes.

In a separate bowl, add the vinegar and 1 teaspoon sugar, then add the sliced onion and let it soak in the vinegar for 5 minutes.

Add the soaked onions to the shawarma and mix very well.

Let it cook for another 5 minutes until done, then remove from heat and serve.