Heat oil in a cooking pot. Add chopped onion and cook until it becomes translucent.
Add finely chopped ginger and garlic. Saute for a few seconds.
Add green peas, sweet corn kernels, and chopped carrots. Cook for a few minutes or until the vegetables are cooked but slightly crunchy. You may add a few tablespoons of water and cover the pot to fasten the cooking process.
Once the vegetables are cooked, add chili flakes, salt, and pepper. Saute for a few seconds.
Add chopped tomatoes and cook for 1-2 minutes only.
Add crumbled paneer and mix everything. Cook for about a minute.
Switch off the stove and add roughly chopped cilantro. Mix.
Take a slice of bread and spread green chutney on it. Spread paneer filling on top.
Apply green chutney on another slice of bread and cover the paneer filling with it. Keep the chutney side down.
Heat a grill pan. Brush it with some butter or olive oil and put the sandwich on it.
Brush the bread slice on top with some butter/ olive oil.
Grill both sides of sandwich until they turn brown and crisp.
Serve hot with a chutney or any dipping sauce of choice.