Pre-heat the oven to 200C/390F
Scrub clean the parsnips, carrot, and potatoes, cut into large chunks and place on a large baking tray
Combine the honey, oil, cayenne, and pepper in a small dish and drizzle over the vegetables, sprinkle over the salt and bake for 40 minutes
Meanwhile, place a large soup pot over a medium heat and melt the butter
Peel and roughly dice the onion and add to the melted butter and saute until translucent
Crush the stock cubes and add to the onions and combine, then quickly add the water and stir until dissolved
Add the roasted vegetables to the soup pot and simmer on a low heat for 10-15 minutes
Cook the bacon in a frying pan until brown then allow to cool on some kitchen paper to drain off any excess fat
Take the soup off the heat and allow to cool for a few minutes before adding the milk
Blend the soup until smooth with a hand/immersion blender, adding a little water to achieve the desired consistency
Cut the bacon into small chunks and stir into the soup
Put back on a low heat until piping hot, then serve