In a mixing bowl, add boiled potatoes and green peas.
Now in a pan, add oil, cumin seeds, hing, green chilli paste and ginger paste. Sauté it.
Then add chopped onion and sauté till it become translucent.
Now lower the flame, add turmeric powder, red chilli powder, coriander powder, garam masala and some water. mix well.
Switch off the gas and add masala into mixing bowl.
Also add salt, lemon juice and some coriander leaves. mix well.
Aloo matar sandwich masala is ready. keep it aside.
For assembling, Take one bread slice, spread butter on it. Then spread green sandwich chutney in it.
Add potato masala and spread it with spoon.
Take another slice of bread, spread butter and tomato sauce on it. place the bread on masala slice and close it.
Apply butter on the top of sandwich.
Place sandwich in grill pan and toast it for 3-4 minutes.
Serve aloo matar sandwich with tomato sauce and chutney