Rinse peas, place in pot, add cold water, set aside for 24 hours.
Roast carrots and parsnips. Make a broth with the bones and smoked bacon, roasted vegetables, allspice and bay leaves. Add the peas and the water it was soaking in to the broth. Boil everything, season with salt and pepper. Remove spices and bones, then add heavy cream and blend into a smooth cream.
Cut the bacon into thin slices and bake until crispy at 180°C for 4-5 minutes.
Pour hot soup into deep plate, place sprouts and crisped bacon on top. Place a tablespoon of sour cream on top.