What a surprisingly simple and comforting veg dish. Unfortunately everyone seems to be completely baffled by celeriac, but it's beautiful in soups or thinly sliced into salads. When roasted it goes sweet and when mixed with potato and mashed it's a complete joy.
Slice about 1cm/½ inch off the bottom of your celeriac and roll it on to that flat edge, so it's nice and safe to slice. Slice and dice it all up into 1cm/½ inch-ish cubes. Don't get your ruler out – they don't have to be perfect. Put a casserole-type pot on a high heat, add 3 good lugs of olive oil, then add the celeriac, thyme and garlic, with a little seasoning. Stir around to coat and fry quite fast, giving a little colour, for 5 minutes.
Turn the heat down to a simmer, add the water or stock, place a lid on top and cook for around 25 minutes, until tender. Season carefully to taste and stir around with a spoon to smash up the celeriac. Some people like to keep it in cubes, some like to mash it, but I think it looks and tastes much better if you smash it, which is somewhere in the middle. You can serve this with just about any meat you can think of.