Cheesy celeriac souffle and citrus salad: Thomasina Miers’ recipes to brighten a dark winter’s day

There is a skill in not wasting food and it’s all about good, old-fashioned housekeeping. If you learn how to store ingredients properly (cool, dark places are handy for spuds, for example) and keep tabs on what’s in your fridge/freezer, you can use everything up before it goes off – and make delicious things in the process. This golden, cheese-crusted souffle uses up the celeriac and spuds left after the festive season, plus any odds and ends of cheeses. It is spectacularly good, especially paired with a sparkling citrus salad.

Celeriac, onion and cheese souffle (pictured top)
Sweet onions, soft roots and lots of cheese rise into a light, golden souffle with none of the fuss of making a bechamel. Bliss!

Prep 10 min
Cook 1 hr 30 min
Serves 4-6

300g celeriac
200g floury potatoes
Salt
45g butter, plus extra for greasing
1 large red onion, peeled and finely diced
1 small handful fresh thyme leaves
1-2 garlic cloves, peeled and finely grated
200g double cream
100g greek yoghurt, or soured cream
250g grated cheese – I use a mix of blueand cheddar
Grated nutmeg
7 eggs, separated

Peel the celeriac and potatoes, then cut them into bite-sized chunks. Put them in a pan filled with 7½cm-10cm salted boiling water, then cook on a high heat for 18-20 minutes, until tender. (Alternatively, if you have leftover cooked potatoes or celeriac, this dish is a lovely way of using them up.)

Meanwhile, melt the butter in a pan, add the onion and season generously with salt, pepper and the thyme. Sweat, stirring, on a medium heat for 10 minutes, then add the garlic.

Drain the roots, then roughly mash them in the pan set over a low heat. Add the the cream and yoghurt, then mash again. Add three-quarters of the grated cheese and heat gently, stirring well, for a few minutes. Stir in the softened onion mixture and season to taste with more salt and pepper, plus a few generous gratings of nutmeg.

Heat the oven to 210C (190C fan)/410F/gas 6½, then beat the egg yolks into the vegetables. In a large, very clean bowl, whisk the egg whites until stiff and immovable, then, using a large metal spoon, gently fold a third of them into the root mash. Fold the veg mix into the remaining egg whites, taking care not to beat out the air.

Pour the mixture into a large, buttered ovenproof ceramic vessel and bake in the centre of the oven for 40-45 minutes; if the top is threatening to brown too much after 30 minutes, turn down the heat to 200C (180C fan)/390F/gas 6. Once the souffle has risen and is smelling glorious, serve at once with the citrus salad below.