1) Heat the oil in pan and sauté the garlic in it. Now add chicken and cook it for 2-3 minutes.
2) Add capsicum, tomatoes, salt, black pepper, mustard powder, red chili, oregano and tomato sauce. Mix it and set it aside.
3) Now scrap the buns from upper side and make a space in it. Fill the chicken mixture in it and spread cheese all over it.
4) Bake it in preheated oven for 2-3 minutes or till the cheese melts. Serve it with tomato ketchup.