Heat the olive oil in a heavy pot over a medium heat. Add the carrots, celery, onion and fennel. Reduce the heat to low and gently cook the vegetables, with the pot covered, for 10-15 minutes until they are all softened but not browned.
Add the tomatoes to the pot with the beets and cook for about 3 minutes longer. Stir in the orange zest with the stock. Bring the mixture to a boil, stirring occasionally, then cover the pot, reduce the heat and simmer for about 25 minutes until all the vegetables are tender.
Meanwhile, prepare the salsa and bagels. For the salsa, simply combine the ingredients together in a bowl. Then, for the bagel topping, blend the cream cheese with the horseradish sauce until well mixed. Toast the bagels, then spread the cheese mixture over the toasted bagel halves.
Remove the soup from the heat, blend in a blender or food processor until completely smooth, then return to the pot. Alternatively, blend the soup in the pot using a hand-held blender. Stir in the orange juice, and a little extra stock if too thick, then reheat gently and season to taste.
Serve the soup topped with a little of the beet salsa and accompanied by the bagels.
Cook's tip: The soup is suitable for freezing but it's best to prepare the accompaniments just before serving to maintain freshness.
Each serving: 8.5 g protein, 7.5 g fat of which 1 g saturates, 38 g carbohydrate, 9 g fibre, 269 Calories