1. Whack the onion and garlic into a big saucepan with the olive oil. Let them start to sizzle over medium heat, then pop the lid on and allow the onion to sweat away in its own juices for 5–10 minutes until translucent, stirring occasionally.
2. Meanwhile, turn the cauliflower upside down and cut into the core at an angle, so that the florets all come off with a pull. Now pull them apart until they’re bite-sized. Set aside.
3. Once the onion has sweated down and is fragrant, add the cabbage, carrot, celery and beetroot. Pour in the stock, then supplement with extra water (preferably filtered) until your pan of choice is three-quarters full. Squeeze in the lemon juice (to keep the brightness of the beetroot) and add a good pinch of salt.
4. Bring to the boil, then reduce the heat and simmer for another 10 minutes. Add the cauliflower florets and cook until the shredded beetroot is easily bitten through, but not mushy and the cauliflower softens slightly; keeping some ‘bite’ here is the key for both flavour and texture.
5. Season to taste with the brine, if using, as well as salt and freshly ground black pepper. Garnish with dill and the reserved celery leaves, and serve with sour cream, grated garlic and croutons – or what you will!