Admittedly, it took quite a while to find a vegetable that could be added to a regular potato soup that would not only integrate well with the flavor of the potatoes, but which would also add nutrition and enhance texture.
1 medium Onion
1/4 Celery Root
6 (or so) medium-sized Russet potatoes.
6 cups Vegetable Stock
Parsely - if desired.
Peel the onion and chop finely.
Quarter the celery root, select a piece, and peel it. Make sure you remove the outer area completely but don't worry about small, deep crevices that remain dark brown - you do not need to remove them - just make sure the remaining root is clean. Cut the celery root into 1/4 inch pieces.
Peel the carrots, slice them in half length-wise, and cut into small pieces.
Slice the leek in half and rinse under running water while fanning out the individual leafs. Ensure that all dirt is removed. Slice the leeks into narrow strips.
Heat 3 tablespoons of oil in a heavy sauce pan over medium heat. Select a sauce pan suffiencnly large to hold at least 8 cups of liquid. Add the onions and cook until translucent.
Add celery root, carrots, and leeks. Cover sauce pan and let cook on medium heat, stiring occasionally, for 10 minutes.
Meanwhile, peel the potatos and cut into 1/4 inch pieces.
Add vegetable stock. I find that adding cold stock shocks the vegetables and thus, prefer to preheat it for a few minutes, either in another pan or simply in the microwave.
Add 1 teaspoon of salt (or to taste) and freshly-ground pepper.
Increase heat, bring to a slight boil, and add the potatoes. Once the soup boils again, reduce heat to medium, cover pan, and let simmer for 25 minutes, stirring occasionally.
Remove a small piece of potato and test for consistency - it should be very soft and no longer have any "bite" to it.
Puree soup to a creamy consistency - either in batches in a food processor or by using a submersible hand blender. If you've wondered how a soup can be creamy without adding actual cream, you will be pleasantly surprised by the wonderful effect of the celery root. It will add the desired creamy consistency without adding all the fat of cream.
If using parsley, chop one tablespoon and add.
If your child loves hot dogs, you can add a thinly sliced hot dog to the soup to make it an even more substantial meal. Allow enough time in the hot soup for the hot dog to warm up (usually just about two minutes or so).
Fresh soup can be very hot. Make eating the soup easier for your child by adding an ice cube to the serving bowl.
Some children really don't like onions - if this is an issue, feel free to leave it out of the recipe altogether.