Pour over 500ml boiling water and leave to steep for 5 mins.

Meanwhile, put 100g blueberries in a jug, add the sugar and lightly crush with the end of a rolling pin or a potato masher.

Remove the tea bags from the water, pour the tea over the blueberries and top up with another 300ml cold water.

Add a large handful of ice to cool quickly, or chill until cold.

2)When you’re ready to pack your picnic, pour the iced tea into bottles or flasks.

Add a few sprigs of fresh mint, some lemon slices and the remaining blueberries.

Seal and store in a cooler bag.