Cut naan into two halves like a sandwich bread and keep aside.
Take a pan add washed and clean kheema, ginger garlic paste, green chilly paste, black paper powder and salt. Cook keema till it changes color and its water gets burn. keep it aside.
Now take another pan and put it on medium flame, add butter and oil, add cumin. saute fora few seconds, add ginger garlic paste, chopped green chillies. add 2 chopped tomatoes,red chilly powder, turmeric powder, Coriender powder, cumin powder, garam masalapowder and salt. mix well and saute till tomatoes becomes pulpy.
Add cooked keema, again 2 chopped tomatoes little water and cook for 2 to 3 minutes,Add 2 chopped onion n again cook for 5 minutes. now add boiled and mashed potatoes corieander leaves, lemon juice and mix nicely.
And the keema mixture is done.
Halve naan horizontally Heat some butter on tawa and toast the naan halves
Make a dip of coriander chutney and mayonnaise.
Apply it on both the sides of naan halves
Put a thick layer of kheema mixture on naan. add some chopped onion on top.
Cover the top half of the naan and place the sandwich back on a hot tawa. Apply butter on top of the sandwiches and cook for 1 to 2 minutes on each side
.Cut into pieces and arrange it on a plate. serve hot