Preheat your oven to 200°C (400°F) / 180°C Fan / Gas Mark 6. Tightly wrap each beetroot in foil, place them on a baking tray, and bake for 50-60 minutes, turning halfway. They're ready when a knife pierces them with no resistance. 2.
While the beetroots bake, peel and chop the potatoes into 3cm chunks.
Place them in a large pan of salted water, bring to a boil, then reduce to a simmer for 5 minutes. 3.
Peel the celeriac, chop it into similar-sized chunks, and add it to the pan with the potatoes.
Top up with water if needed and simmer for another 10-15 minutes, or until both are tender. 4.
Drain the potatoes and celeriac well, then mash them until smooth.
Stir in the butter, season generously with salt and pepper, and return the pan to a very low heat for 5-10 minutes to evaporate any excess moisture, stirring occasionally.
Set aside. 5. Toast the hazelnuts in a dry frying pan over medium heat until golden and fragrant. Be watchful as they can burn quickly!
Pour in the sunflower oil, immediately remove from the heat, and let it cool to infuse. Decant the nutty oil into a small bowl. 6.
Once the beetroots are cooked and cool enough to handle, the skins should slide off easily.
Slice off the tops and bottoms, then cut each beetroot into four wedges. 7. Core the apples (no need to peel) and cut each one into eight wedges. 8. Wipe out the frying pan you used for the nuts.
Add the brown sugar and melt it gently over a low heat.
Once it starts to liquefy, carefully pour in the sherry vinegar – stand back to avoid the pungent steam! 9.
Add the apple wedges to the pan, tossing them to cook and coat in the glaze. As they begin to soften, add the beetroot wedges and season.
Continue to cook until everything is sticky and beautifully glazed. 10. To serve, spoon a generous portion of the warm celeriac and potato mash onto each plate.
Top with the glazed beetroot and apples, and finish with a drizzle of the infused hazelnut oil.
