Preheat oven to 180°C.Put spring onion bulbs, green chillies, spring onion greens, cheese in a bowl and mix well. Crush garlic cloves into the bowl and mix well.
Cut potatoes into thick slices and arrange some of them in a single layer in a baking dish. Spread some chilli-cheese mixture on top and arrange another layer of potato slices on top. Repeat the layers once.
Pour 1 cup milk and sprinkle salt on top. Repeat these layers with remaining potato slice and chilli cheese mixture. Pour the remaining milk on top.
Place dish in the preheated oven and bake for 10 minutes. Reduce temperature to 170°C and bake for 40 minutes.Serve hot