You need only a small spoonful of this as it is rich with cream. Make it a day ahead and it only needs reheating in the oven on the day.
650g/1lb 7oz parsnips, peeled and cut into even chunks
650g/1lb 7oz swede, peeled and cut into chunks as parsnips
142ml tub soured cream
1 rounded tbsp hot horseradish
2 tbsp fresh thyme leaves, plus extra for garnish
butter for greasing
25g/1oz parmesan, coarsely grated
FOR THE BUTTER TOPPING
50g/2oz butter
1 small onion, peeled and finely chopped
50g/2oz fresh white breadcrumbs
a small handful of thyme leaves, plus extra for scattering
Takes 1¼ hours–1 hour 40 minutes • Serves 10, with other veg
1 In a large pan of boiling salted water, cook the parsnips and swede for about 20 minutes until tender. Drain, then mash until smooth. Stir in the soured cream, horseradish and thyme and season. Spoon into a buttered, shallow ovenproof dish. Set aside.
2 Make the topping. Melt the butter in a frying pan and cook the onion for 5–6 minutes, until golden. Mix in the breadcrumbs and stir to brown lightly and crisp. Season and add the thyme. Take the pan off the heat. Spoon the mixture over the mash. Scatter over the parmesan. (Can be made a day ahead and kept covered in the fridge.)
3 Preheat the oven to 190°C/Gas 5/fan oven 170°C and bake for 35–40 minutes if doing from cold 25–30 minutes if not – until golden and crisp. Serve scattered with more thyme.
• Per serving 158 kcals, protein 4g, carbohydrate 17g, fat 9g, saturated fat 5g, fibre 5g, added sugar none, salt 0.57g