Boil 100 grams of sweet corn kernels in water for 5-7 minutes until they are cooked. Drain the water and set the corn aside.
In a mixing bowl, add the boiled corn, 100 grams of grated cheese (preferably mozzarella or cheddar), 1 finely chopped onion, 1 finely chopped green chili, 1/2 teaspoon of black pepper powder, 1/2 teaspoon of chaat masala, and salt to taste. Mix well to combine all the ingredients.
Take 8 slices of bread (white or brown) and spread a thin layer of butter on one side of each slice.
Place a generous amount of the corn-cheese mixture on the buttered side of 4 bread slices, spreading it evenly. Cover each slice with the remaining 4 slices, buttered side facing down.
Preheat a sandwich maker or a non-stick pan on medium heat. Place the sandwiches in the sandwich maker or on the pan and cook until they turn golden brown and crispy on both sides. If using a pan, gently press the sandwiches with a spatula and flip them carefully to cook both sides.
Once cooked, remove the sandwiches from the sandwich maker or pan and let them cool for a minute. Cut each sandwich into halves or quarters and serve hot with ketchup or chutney.