Beetroot dauphinoise

I was totally delighted when I made this with golden beetroots as the beets turned the creamy sauce a delicious golden colour and infused if with a gentle beetrooty earthiness that never happens when you make dauphinoise with potatoes! If you make it with red beetroots (or a mix) it will be delightfully pink! This also works well with other vegetables mixed in with the beets - potatoes, turnips, squash - just make sure you slice the vegetables as thinly as you can to make sure they cook through. I’ve flavoured the cream with thyme leaves for this version, but I think rosemary and/or nutmeg would work really well, and if you are feeling adventurous a dollop of wholegrain mustard or horseradish in with the cream would be delicious!

Serves 6-8

3 large onions, peeled, halved and cut into thin semi-circular slices
50g butter
Dash of olive oil
8 garlic cloves, thinly sliced
1 KG beetroots (or use a mix of beets and potatoes), scrubbed but not peeled
600ml double cream (or use half cream and half milk)
3 sprigs of thyme, leaves picked off the stems
100g hard cheese, grated. I like to use something Alpine like gruyère or St Gall but parmesan or mature cheddar would also work well
Salt and black pepper

1. Preheat the oven to 160°C fan. Use 10g butter to grease the bottom and sides of an ovenproof dish approx. 30cm x 20cm x 5cm – although this recipe will work with a slightly smaller dish too, the finished dauphinoise will just be deeper.

2. Put 40g butter with a dash olive oil into a wide casserole or frying pan over a medium heat. Once the butter is bubbling add the sliced onions with ½ teaspoon salt and cook over a medium heat, stirring frequently, until the onions are soft and have started to turn a delicious, golden brown. This will take about 20-30 minutes. Add the sliced garlic and cook for another couple of minutes then turn off the heat.

3. While the onions are cooking thinly slice the beetroots, they should be 2-3mm thick. I slice the beetroots with a mandolin, but you can use the slicer on your food processor or slice them with a very sharp knife. If you are slicing them by hand I recommend cutting them in half so you have a flat surface against the chopping board.

4. Arrange 1/3 of the beetroot slices in the bottom of the buttered ovenproof dish, add ½ cooked onions over the beets and sprinkle over 1/3 thyme leaves. Add another layer of beetroot slices (1/3) and then the remaining onions and another 1/3 thyme leaves. Arrange the final layer of beetroot slices on top.

5. Season the double cream with a generous ½ teaspoon salt and lots of black pepper, whisk to mix and dissolve the salt. Pour the cream mixture over the layers of beetroot. It won’t cover the beetroot but don’t worry as lots of liquid will be released by the vegetables as they cook. Sprinkle over the grated cheese, remaining thyme leaves and a final grind of black pepper.

6. Put in the oven and cook for 1 hour 15 minutes. Check after 45 minutes and if it looks too dry add a little milk or water. If it isn’t browning enough on top (it should be golden and bubbling) turn the temperature up for the last 15 minutes of cooking time.

7. Allow to cool for 15 minutes before serving. This is a great side to roast chicken but it also excellent served as a main course with a green salad on the side.