Here, a little egg white combines with a sprinkling of thyme and a lot of salt to form a dramatic and extremely effective self-seasoning oven. It’s an excellent way of cooking and eating the ugly duckling of the vegetable world, and results in a flavoursome, well salted, tender and surprisingly juicy side. It’s the perfect accompaniment to roast game or other roast meats, but is also great with white fish like hake, cod and sea bass. Best of all, although dramatic looking, it’s neither difficult nor time-consuming to pull off.
The celeriac will stay fairly warm for 30 minutes once out of its casing if you leave it whole and wrap it in foil. To serve, I like to slice the celeriac into steaks, then drizzle them with peppery olive oil to finish.
Ingredients
- 1 celeriac (800 g–1 kg)
- 120 g egg white (about 3 large eggs)
- 500 g fine table salt
- Leaves from 8–10 sprigs thyme
- Extra-virgin olive oil, to serve
- Preheat the oven to 200˚C/Fan 180˚C/Gas 6. Slice off the gnarly, hairy, rooted base of the celeriac, but leave the rest of the skin on. Give it a quick rinse.
- Put the egg whites in a bowl. Add a pinch of salt and whisk for about 30 seconds just enough to loosen the protein in the egg whites. Pour in the rest of the salt and whisk it into the egg whites for 30 seconds or so. This will result in a paste that’s a little wet, but just holds its shape if you prod it. Stir in the thyme.
- Put a spatula-worth of salt paste on the base of a baking tray. Spread it out just a little, then put the celeriac on top (flat-side down). Now cover the celeriac with the paste, as if icing a cake. When it’s all on and there are no obvious holes, put your celeriac igloo on the bottom shelf of the oven. Check it after 4–5 minutes. If some of the paste is slipping down, remove it from the oven and patch up any holes. The egg white and salt will hold firm from now on. Bake for 90 minutes. The crust will be brown and the celeriac inside will be tender but not yet mushy.
- Allow the celeriac to rest for 15–20 minutes in its casing, where it will carry on steaming. Once that time is up and the outside is cool enough to handle, cut round the top with a serrated bread or carving knife. Pull the rest of the shell away and carefully remove your prize. Brush any excess salt off the celeriac’s skin. Slice it into 3cm-thick steaks, then cut those into smaller portions and drizzle with oil to serve.
