The addition of fruit to butter brings a natural sweetness. For 300g, follow the butter recipe to make half as much. Food process 140g strawberries, hulled and chopped into small pieces, then add the butter, pulsing a few times to combine. Transfer to a bowl, then knead the butter, until the strawberries are combined. Add a further 140g strawberry pieces and massage again. Sieve in 100g icing sugar and mix in. Transfer to a large sheet of baking paper and use it to roll the butter into a long sausage shape. Wrap the paper around it and twist the ends. Chill for 1 hr. Spread on muffins or scones. The butter wiil keep for 3 days in the fridge.