I briefly googled recipes. Lots of milk, cream, potatoes. Wasn't into that. I did notice a few incarnations using cauliflower. So I decided that since cauliflower and cabbage are in the same family and I had lots of cabbage that would be the main pairing.
For flavor without the use of cream or butter I went with an onion based broth. I went with a fairly light, weak broth as to not overtake the celeriac.
Small sweet onion skin and 1/4 cup of the flesh diced
3 cloves garlic roughly chopped
2-3 ribs/seeds jalapeno and 1 tbl of the diced flesh
2 tbls dill pickle juice
1/4 cup dry white wine
1 cup water
1/4 tsp each salt and black pepper
Bring all elements to a boil and then lower heat and simmer for 5 minutes.
1 peeled, chopped celery root, 1/4 inch pieces
1/2 cup roasted white cabbage
1 tsp olive oil
1 tsp turmeric
salt and pepper to taste
To roast the cabbage heat oven to 450 F. Have a rack one step up from the bottom of the oven.
Fill a sheet pan with roughly chopped cabbage. Drizzle with olive oil and sprinkle with salt and pepper. Stir to coat.
Roast for around 15 minutes. Stirring halfway through. Roasting until at least 1/4 of the cabbage has charred and all of it has wilted.
Peel and chop the celery root into small pieces. Add to simmering broth. Continue simmering for about 7 more minutes until celery root is tender. Simmer with no lid on the pot to allow the broth to reduce. Once the liquid has reduced by half, add a lid to the pot for the rest of the cooking time.
Add all contents of broth and celery root, including hot liquid to a blender. Also add your roasted cabbage, and your 1 tsp of olive oil. Season with salt, pepper and turmeric. Puree until smooth. Taste. Adjust spices if needed.
Careful with the salt. The dill pickle juice added some extra salt already.
Serve warm or let cool in the fridge for a slightly thicker consistancy.
It has a similar taste to pea soup. It's good straight up. Also on salads, roasted potatoes, sandwiches.
Photo is the celery root puree, a salad of kale, charred cabbage and red beans, spicy marjoram lentils and barley and a hot chile de arbol and roasted tomato sauce.