Firstly, pressure cook potatoes for 3-4 whistles. Wait till it cools.
Once cool, peel off the skin, and mashed them well with a potato masher or with a back of a ladle.
Further, take a bowl and add mashed potatoes with all the spices: roasted cumin seeds, coriander powder, red chili powder, mango powder, salt, and garam masala.
Additionally, add finely chopped green chili and fresh coriander leaves (cilantro).
After that, mix all the ingredients very well.
Now take a slice of kulcha and spread some tomato ketchup.
Further, spread some aloo masala/potato masala on the kulcha.
After that, cover it with other plain kulcha.
Heat a pan/tawa and grease some butter/ghee on the tawa.
Further, place the potato stuffed kulcha on the heated pan.
Grease the butter/ghee on the other side now.
Further, press down gently with a spatula and grill the kulcha sandwich until both sides are crispy and golden brown.
Finally, cut the aloo stuffed kulcha sandwich and serve it hot with green chutney or tomato ketchup.