Chocolate, beetroot & pistachio brownies

Preheat the oven to 180ºC, gas mark 4. Place the chocolate and butter in a heatproof bowl, set over a pan of simmering water and heat, stirring occasionally, until melted. Remove and set aside to cool for 5 minutes.

Grease a 20x27cm baking tin, then line it with baking parchment. Combine the cocoa, flour, baking powder and salt in a bowl. Blend the beetroot in a blender or food processor until smooth or finely chopped. Pour in the melted chocolate mix and blend some more until smooth.

In a separate bowl, beat the eggs and sugar together using an electric hand mixer, until doubled in volume. Stir in the chocolate and beetroot mixture. Using a large metal spoon, fold in the dry ingredients.

Pour the batter into the prepared tin and spread out using a palette knife. Scatter with pistachios and the sea salt flakes, if using, then bake for 25-30 minutes, until set to the touch but still gooey inside. Cool on a wire rack before cutting into 12 pieces. Serve warm with ice cream, if liked.