Melt the butter in a heavy-bottomed saucepan. When the butter has stopped foaming, add the parsnips, apple, and onion. Sauté until the onion is translucent and soft, about 5 minutes.
Add the coriander, water, and bouillon cube. Bring the soup up to a gentle simmer, turn down the heat, and simmer until the parsnips are tender enough to be easily pierced with a fork.
Remove the soup from the heat and with a hand-held blender, purée the soup. You will need to let the soup cool down before blending.
After blending the soup, strain the contents through a fine-mesh strainer to remove any lumps. The soup can be made ahead up to this point and refrigerated for several days. Warm gently before continuing.
Stir in the cream, and season to taste with the salt and pepper. Let the soup get hot, but do not boil. Adjust the consistency, thinning with a little water if needed.
For the garnish, whip the heavy cream until stiff peaks form, then fold the Parmesan and 1 tablespoon of the chives into the whipped cream.
Grate some of the apple into the bottom of four warm soup bowls, and ladle the soup on top. Spoon the Parmesan cream on top of the soup, and garnish with the remaining 2 tablespoons of chives.
