Clean the chicken mince and keep aside.
Heat oil in a pan, add garlic, chopped onion and sauté for a minute. Add half the chopped green chillies, chicken kheema and sauté for two to three minutes.
Add turmeric powder, salt, red chilli powder and stir. Add chopped tomatoes, chopped coriander leaves, garam masala powder and mix. If the kheema forms any lumps, break them gently.
Add salt, butter, cream and the remaining chopped green chillies to mashed potatoes and mix well. Put the mixture in a piping bag with a star nozzle.
Keep stirring the kheema till it is well cooked. Put the kheema in a glass baking dish. Pipe the creamed potatoes on top making rosettes. Bake or grill till the potatoes turn a golden colour.