In a bowl, mix 200 grams of hung curd, 1 teaspoon ginger-garlic paste, 1 teaspoon red chili powder, 1/2 teaspoon turmeric powder, 1 teaspoon garam masala, 1 teaspoon chaat masala, 1 tablespoon lemon juice, and salt to taste. This will be your tandoori marinade.
Cut 250 grams of paneer into small cubes and marinate them in the prepared tandoori marinade for at least 30 minutes.
Preheat your oven to 200°C. Place the marinated paneer cubes on a baking tray lined with parchment paper and bake for 15-20 minutes, or until the paneer turns golden brown.
In a separate bowl, mix 1/2 cup finely chopped onions, 1/2 cup finely chopped tomatoes, 1/2 cup finely chopped capsicum, 1/2 cup grated carrot, and 1/4 cup chopped coriander leaves. Add salt and pepper to taste.
Apply butter on one side of 8 slices of bread. On the unbuttered side, spread a layer of green chutney, followed by the mixed veggies, and then the baked tandoori paneer cubes.
Place another slice of bread on top, with the buttered side facing outwards. Repeat for the remaining sandwiches.
Heat a non-stick pan or sandwich maker and cook the sandwiches until they turn golden brown and crispy on both sides.