Method
Prep:35min  ›  Cook:50min  ›  Ready in:1hr25min 

1. Place the oil in a large saucepan and add the onion. Set aside 55 g (2 oz) of the carrot for the mash, then chop the rest and add it to the pan. Mix well, cover and cook over a moderate heat for 5 minutes to soften the onion.
2. Place the lemon juice in a small bowl. Cut the bulb of fennel into quarters. Finely grate one quarter into the lemon juice and toss well. Finely grate the reserved carrot and add it to the grated fennel. Cover and set aside.
3. Chop the remaining fennel and add to the saucepan. Peel and dice the beetroot, and add it to the pan. Pour in the stock and bring to the boil. Reduce the heat, cover the pan and simmer for about 30 minutes or until all the vegetables are tender.
4. Meanwhile, bring another pan of water to the boil. Add the potatoes and boil for 10 minutes or until very tender. Drain the potatoes well and return them to the pan. Place over a low heat for about 1 minute to dry, shaking the pan occasionally to prevent the potatoes from sticking. Remove from the heat and set aside, covered to keep hot.
5. Purée the soup in a blender or food processor until smooth, or purée in the pan using a hand blender. Return the soup to the pan, if necessary, and reheat. Taste and adjust the seasoning.
6. While the soup is reheating, set the pan of potatoes over a moderate heat and mash until completely smooth, gradually working in the milk. Stir in the yogurt, grated fennel and carrot, spring onions and seasoning to taste.
7. Divide the mashed potato among 4 bowls, piling it up in the centre. Ladle the soup around the mash and sprinkle with chopped fennel or parsley. Serve at once.

Some more ideas

Other delicious raw vegetable additions to mashed potatoes are finely chopped celery, grated celeriac, finely shredded red or Savoy cabbage, shredded Brussels sprouts and coarsely chopped spring onions. They all contribute extra vitamins and minerals. * Serve the borscht chunky instead of puréed, and add 2 tbsp hazelnut oil to the mashed potatoes instead of the yogurt. * Instead of spooning the borscht around a pile of mash, garnish each bowl of soup simply with 1 tbsp Greek-style yogurt, soured cream or creamed horseradish, then sprinkle with chopped fresh fennel or parsley.

Plus points

Beetroot is a particularly rich source of the B vitamin folate, which may help to protect against heart disease and spina bifida. It also provides useful amounts of iron. The characteristic deep red colour comes from a compound called betacyanin, which has been shown to prevent the growth of tumours in animal studies. * Adding grated raw vegetables to mashed potatoes is a good way of including them in a hot meal, especially for children. * Fennel contains phytoestrogen, a naturally occurring plant hormone that encourages the body to excrete excess oestrogen. A high level of oestrogen is associated with increased risk of breast cancer. Fennel also contains useful amounts of folate.

Each serving provides

A, folate * B1, B6, C * iron