I've never cooked celeriac in its skin before. Knobbly and tough, covered in warts with rooty tentacles, it holds onto dirt and looks unpalatable.
A while back I stumbled across a Rene Redzepi recipe from Noma for pot roasted celeriac. Unfortunately it called for young celeriac roots, smaller than a fist, which you never see on the supermarket shelves. As usual though, the local Food Co-op came to the rescue last month as I saw a box of mini-celeriacs for sale. So naturally I pounced and had to try the recipe out...
The method is simple. Clean the celeriac. I used a chopstick to gouge out all the muck from the root base and a scouring pad to brush off any remaining dirt. Heat a couple of tablespoons of olive oil in a large saucepan. Add the cleaned celeriac and seal, like a joint of meat, turning every few minutes until golden. Add some butter, a cup of water and cover with a lid. Turn the heat down and cook gently for an hour. Turn the celeriac and baste occasionally, adding more water if the pot dries out.
While the celeriac is roasting - make the buttermilk sauce.
Slowly warm 200ml of milk in a saucepan and add the juice from half a lemon. Be careful not to overheat of else it will curdle. Whisk in two tablespoons of olive oil and season with salt.
Take out the celeriac and cut them in half. Spoon out the warm buttermilk sauce, and scatter over more olive oil and a squeeze more of lemon juice. Serve.