Preheat the oven to 160°C.
Place red onion, peppers and chilli on baking tray, drizzle with olive oil and roast for 10-15 minutes until skins start to blacken. Remove from oven, leave to cool slightly, remove skins and chop. Set aside.
In separate small saucepan add milk and Knorr Chicken Stock Pot. Heat gently to dissolve the stock pot, stir well and remove from heat once stock is melted. Set aside.
Grate the blanched potatoes into a large bowl, add the Stork Margarine and mix well. Pour in the milk and stock mixture. Add the chopped onions, peppers and chillies. Add half of the grated cheese and mix through well.
Place the mixture in a medium sized casserole dish and cover with remaining grated cheese. Place in oven and cook for 15-20 minutes until the potato is cooked through and the cheese is starting to brown.
Heat a non-stick pan, add the bacon and cook for 5 minutes until cooked. Sprinkle the cooked bacon over the top of the casserole to serve.