Mary Berry's chocolate ... beetroot. Spoon into the prepared tin and bake for about 35 minutes, or until risen and springy to the touch. Remove and set aside to cool before icing. To make the ...

Make sure you buy plain cooked beetroot, not the type stored in vinegar. Grease and line a 30x20cm/12x8in rectangular brownie tin. Put the chocolate and butter in a heatproof bowl and put in the oven.