Boil potatoes whole or cubed however you prefer. You can steam or pressure cook the whole potatoes in a pressure cooker or in a instant pot. You can also boil them in a pot, covering with enough water. Cook them until fork tender. Cool them and peel.
Add ginger, garam masala, red chilli powder, turmeric, salt & green chilli to a mixing bowl.
Optional - Heat 1 tsp ghee in a small pan and pour it over the spices to bring out the aroma.
Add the boiled potatoes and mash them. Mix everything well and taste test. Add more salt and spice if needed. When the mixture slightly cools down, squeeze in the lemon juice.
How to make potato sandwich
Spread butter over the bread slices. If you want you can also spread green chutney or schezwan sauce or any other sauce on the other side.
Then spread the potato masala. Cover with another bread slice with the buttered side out. Then toast the sandwiches in a preheated hot toaster until golden and crisp.
You can also air fry on 360 F (180 C) for 3 mins in a non-preheated fryer. Or for 2 minutes in a preheated air fryer.
Alternately you can toast these aloo sandwiches on a griddle. The other option is to simply toast them in oven for 5 to 6 mins at 360 F or 180 C.
Serve potato sandwiches hot with tea or any sauce.