Slit each hot roll horizontally, scoop the centre of each halve a little, using a spoon so that a light depression is formed for the topping. Brush the scooped bread halves with a little melted butter on both the sides and bake in a pre-heated oven at 180°c (360°f) for 5 to 7 minutes or till they turn crisp. Keep aside. Heat the butter in a broad non-stick pan, add the green chillies and sauté on a medium flame for a few seconds. Add the plain flour and cook on a medium flame for 30 seconds, while stirring continuously. Add the carrots and green peas and cook on a medium flame for 1 minute. Add the milk and cheese, mix well and cook on a medium flame for 1 minute. Add the paneer, salt and pepper, mix well and cook on a medium flame for 1 more minute. Divide the topping into 6 equal portions. Keep aside. Place a portion of the topping evenly over each hot dog halve, sprinkle ½ tbsp grated cheese over it and bake in a pre-heated oven at 180°c (360°f) for 5 minutes or till the cheese melts. Serve immediately topped with chilli sauce.