1. Trim the leek, only retaining the white and slightly green part, discard the rest.
2. Clean the leek by cutting it vertically in half, wash thoroughly.
3. Slice the leek in 1/8 inch slices and set aside.
4. Peel and dice the onion, set aside.
5. Slice the Little potatoes in half.
6. Peel and slice the carrots,
7. Peel and dice the celeriac, place in a bowl of water so it won't brown with a bit of lemon juice.
8. Melt the butter in a large saucepan over medium heat.
9. Add the onion and leeks and sauté until softened for about 5 minutes.
10. Add the carrots and drained celeriac and continue to sauté for 2-3 minutes.
11. Pour in the chicken broth and add the potatoes.
12. Add the nutmeg, thyme, and season with salt and pepper.
13. Bring to a boil, reduce heat, and simmer with the lid on for 25 minutes.
14. Stir in the cream and adjust the seasonings with salt and pepper.
15. Garnish with chopped parsley.