The most difficult soup I've ever made, but well worth the effort.
In a medium size saute or frying pan melt the butter and add the carrots, celery, onions, and leeks. Season with salt and cover pan. Reduce the heat to very low and cook very slowly, stirring occasionally, 30 to 35 minutes, until the vegetables are tender.
Make the dumplings; fill a wide deep pot with boiling water and bring to a simmer. Combine the water, butter, and 1 tablespoon of salt in a medium saucepan and bring to a simmer over medium-high heat. Reduce the heat to medium and add the flour all at once. Mix rapidly until the dough pulls away from the sides of the pan and the bottom of the pan is clean. Continue to stir another 4 to 5 minutes. When enough water has evaporated from the dough it will steam.
Immediately transfer the dough to a bowl. Add the mustard and the remaining 1/2 teaspoon salt. Mix with a spatula to incorporate. While stirring add the eggs one at a time, beating until completely incorporated. Then mix in the chives.
Shape the dumplings using the sides of two spoons to form three-sidede foot ball shapes. Place a small piece of dough in the first spoon and transfer to the second spoon along the spoons sides. Transfer back and forth until the desired shape has been achieved. Cook the dumplings in the bowling water in batches to avoid crowding for about 5 minutes. Test for doneness, and set aside.
Add the chicken stock to the vegetables and simmer for 30 minutes. Then strain and reserve the soup base.
Peel the celery stalks with a peeler. Cut each stalk crosswise on a diagonal into 1/4 inch thick pieces, until you’ve produced 1 1/2 cups. Cook the celery in a large pot of boiling salted water until just tender; cool in an ice bath or under cool running water, and drain.
Cut the carrots lengthwise into quarters, then crosswise into bite-sized pieces, until you’ve produced 1 1/2 cups. Put the carrots into a small saucepan with the honey, bay leaf, thyme, garlic, a pinch of salt and pepper, and cover with water. Bring to a simmer and cook 4 to 5 minutes, or until just tender.
Produce a roux in the bottom of a large stock pot by melting butter and combining with flour. Slowly add the stock a bit at a time to the roux making sure to bring the mixture to a boil and completely incorporate each time. Simmer for 30 minutes.
Add the dumplings, chicken, carrots, celery, and chives tot he soup and heat through. Season with the vinegar, salt and pepper to taste. Transfer to a bowl for serving and sprinkle with parsley.
By Alex Gibbons