Preheat oven to 180-degree Celcius.
Heat oil in a non-stick pan over medium flame. Add chopped onions. Saute until slightly golden.
Add ginger-garlic paste and cook till the raw smell disappears.
Then add chopped tomatoes and salt. Cook until oil begins to separate.
Add red chilli powder, turmeric powder, black pepper powder and garam masala powder. Give it a mix and cook for 2-3 minutes.
Add the chicken pieces and mix it well.
Saute for a minute then add water and cover it with a lid. Cook until the chicken is fully cooked.
Turn the heat off and shred the chicken.
Cut the buns in half across the length and place it on the baking tray.
Pour the shredded chicken and spread it evenly.
Add a layer of grated cheese over the chicken.
Place the top back on. Apply a mixture of butter and dried parsley over the top of the buns.
Bake for 10 minutes or until the top of the buns are golden brown. Serve.