750 millilitres cold filtered still or sparkling water, depending on your preference
Ice, to serve
Fresh blueberries, to serve
Lemon slices, to serve
To make the blueberry simple syrup, combine the agave with 100 millilitres water in a saucepan set over a medium heat. Stir in the blueberries and bring to a boil then reduce the heat and simmer until the blueberries have broken down, and the mixture is slightly syrupy.
Strain the syrup through a fine sieve and set aside to cool.
In a large pitcher, jug or bowl (depending on how you want to serve your lemonade) whisk together the blueberry syrup, lemon juice and still/sparkling water.
Serve in glasses with ice, fresh blueberries and lemon slices.