Prepare a marinade by combining curd red chilli powder, chaat masala, black pepper powder, and mustard oil. Marinate tofu slices carefully. Sprinkle some salt. Grill the brown bread slices on a grilling pan. Transfer the grilled bread slices to a plate. Heat butter in another pan. Grill the slices of green bell peppers tomatoes, and onions. Carefully grill the marinated tofu slices in the same pan. Transfer the grilled vegetable slices and tofu slices to a plate. Apply mayonnaise on one side of the grilled bread slice. Apply green chutney on the other grilled bread slice. Place a few iceberg lettuce leaves on one bread slice. Top with the grilled vegetables and tofu slices. Cover with the other bread slice. Cut the sandwich in triangles. Garnish sandwich with iceberg lettuce and tomato slices.