Hello Jiji - back online again and see you have a question - my thought was to perhaps mix a little into the normal food and then try mixing more of it into the normal food with less of the sachet meat and gradually change the ratio of sachet meat to steamed chicken until your cat will eat plain cooked food.
You can also, give your cat just the mixed version. Ready made foods out of sachets tend to be made up to balance the nutritional requirements of cats so if you are feeding cooked foods, you may like to add supplements.
I think Janee suggested some good ones but if you are in Saudi Arabia, you may not have a Pets@Home or Tescos ... not sure what sort of products you have available in your country.
I know the story about the big eyes thing ... my Maine Coon has big eyes when he is hungry but he is not a foodie ...
I wish you well with the dieting and your little Persian boy - be strong - for his sake.
