Add butter in a pan and let butter melt.
Add garlic and saute on low heat until garlic turns slightly brown.
Then add flour and saute for couple of seconds.
Add corns and saute well.
Thereafter add spinach and give a good mix.
Cover the pan with a lid and spinach cook for about 5-7 minutes.
Uncover. Spinach is reduced a quite.
Pour milk and add salt, red chilli flakes, black pepper powder and mix well.
Let milk simmer for 2-3 minutes.
Lastly add mozzarella cheese and mix.
Keep the consistency of mixture slightly loose.
Keep the pan off the heat and let the spinach mixture cool down completely.
Take a slice of bread and spread some of the mixture evenly on all sides.
Place another slice of bread over the filling.
Put the bread pair over a long legged microwave rack. (In case you don't have microwave, you can grill bread from both sides on grill pan or normal tawa/skillet after applying butter.)
Apply butter on the top of the bread.
Place second small legged microwave rack over the bread if you interested in giving that grilled look to your bread but don't own a grill pan.
Grill in microwave on high powder (900) for 5 to 6 minutes or until bread attains good brown texture.
When bread is done from one side, turn the side of bread, apply butter, put rack over the bread and grill to desired colour and crunch.
Once bread is grilled from both sides, cut it diagonally.
Enjoy with tomato ketchup or any dip of your choice.