I made a yummy two dish meal component the other day: celeriac mushroom puree. I turned it into pasta sauce the first day and then 2 days later, it was delicious soup.
2 celeriac roots, cubed
2 small onions (or 1 large...) sliced
~1/2 cup dried shiitake mushrooms
Toss the onions in a pan (I used my trusty 12" cast iron) with the (heated) olive oil on medium-low. Once they have started to soften, add the celeriac. I turn the heat up a little bit, but not too much. The point is a long, low cook with occasional stirring to get everything sweet and caramelly.
While this is happening, rehydrate the mushrooms. Put them in a bowl and pour enough hot water over them to cover.
Once the celeriac has started to brown up a bit, you can add a bit of water and cover - I did this instead of parboiling, just to make sure it was getting cooked all the way through. The water also helped deglaze the pan, next time, I might try stock or white wine.
When the celeriac is done getting very nearly close to done (everything should be a nice goldeny brown colour and the celeriac should be soft and break apart easily), drain the mushrooms and reserve the liquid. Put the liquid, along with the celeriac and onion mixture into a blender and puree. You may need to add water.
Return the puree to your pot, slice up the mushrooms and toss them in with the puree. Flavour, to taste, with white pepper and salt.
For pasta sauce, I made a roux, included some nutritional yeast with the flour and added my delicious puree. Remember to cook it to a point where it is less thick than you want it as as soon as it starts to cool, it will thicken up.
For soup, I melted several cubes of leek stock that I made and froze a few weeks ago and added the puree. Simple, quick and delicious, we had it with yummy Gary's Bread (a sort of whole wheat sour dough made from locally grown and milled flour) from Wide Awake Bakery.