Prepare the mushrooms. Place the defrosted honey mushrooms on a baking sheet and dry at 200 degrees until lightly golden brown. While the mushrooms are browning, start making the broth.
Make the broth. Place half an onion, chopped carrots, celery roots and parsley in a soup pot. Cover with water and bring to a boil. Add bay leaf, peppercorns and salt to the broth. Reduce heat and simmer for about 15 minutes until the carrots are done. Cool slightly, then strain the broth, removing all the vegetables and spices.
Prepare carrot chips for serving. Remove the mushrooms from the oven, remove them from the baking tray and line the baking tray with baking paper. Arrange the carrot slices on the paper and bake for 10-15 minutes until light and crispy chips form. Cool and break the chips into 2-3 pieces.
Make the soup. Bring the broth to a boil again, add the dried mushrooms and potatoes. Taste the soup and add salt and ground black pepper to taste. Reduce the heat and simmer the soup for about 20 minutes until the potatoes are done. Turn off the soup and add the chopped greens.