Soak chana for 2 hrs then cook the chana in pressure cooker for 3 whistles.
Heat oil in a vessel and add finely chopped onions.
When onions becomes translucent, add finely chopped tomatoes, mix well and cook for 2-3mins.
Add turmeric, chilli powder, coriander powder, garam masala and salt and cook for 3-4 mins.
When tomatoes become mushy. Add boiled chana or chickpeas and cook for 5 more minutes. Here I had used boiled chickpeas readily available in the market. If you were boiling the chana at home itself then follow the first step else skip.
Now smash the chana slightly to become mushy. If we do so then chana will not be rolled out when we prepare sandwich. Chana masala can be placed like a patty.
Toast the bread slices on the pan or in the toaster to golden on both sides.
Place 2 or 3 tbsp of chana masala over the bread slice and put the other slice over it.
Chana masala sandwich is ready. Serve hot.