1

Heat the oven to 160°C. Grease a 20cm brownie tin with a little butter and line the base with baking parchment.

2

Tip the walnuts onto a roasting tray, then toast in the oven for 6-8 mins until nicely golden and smelling amazing. Set aside to cool. Once cool, roughly chop.

3

Drain the beetroot, roughly chop then blitz to a thick purée in a blender or food processor. Roughly chop the dark chocolate, then weigh 100g into a small bowl and set aside.

4

Put the remaining 200g dark chocolate into a heatproof bowl with the butter. Melt together over a pan of barely simmering water or in a microwave, zapping on high in 30 second intervals then stirring until melted.

5

Measure the sugar into a large bowl. Crack in the eggs then use an electric whisk to beat until the mixture is light and aerated – it should double in size. Add the beetroot purée, melted butter and dark chocolate, flour and cocoa powder along with a big pinch of sea salt. Whisk together until you have a smooth, rich brownie batter.

6

Scrape half the batter into your lined tin. Scatter over half the chopped dark chocolate and chopped walnuts. Top with the remaining brownie batter, smoothing into all the corners, then poke in the remaining chocolate and walnuts.

7

Bake in the centre of the oven for 25-30 mins until the edges are set and the centre still has a nice wobble. Once out of the oven, sprinkle with a little extra sea salt if you like.

8

Leave to cool then cut into 16 squares, to serve.