Rinse the strawberries quickly under cold running water. Shake dry, then trim off the stems. If very large (as supermarket strawberries tend to be) cut them into halves or quarters and place in a large mixing bowl.

Dust the strawberries with sugar and toss the bowl until they are lightly coated, then squeeze the lemon juice on top, together with a few drops of Cointreau if using. Toss the bowl again, then leave the strawberries to rest for a few minutes, until the sugar has melted and the strawberries glisten.

Add enough wine to the bowl to just cover the berries. Let rest for a good hour or so, or longer if you like. If macerating for a long period, put them in the fridge, and take them out at least 30 minutes before serving. Taste and adjust for sugar about halfway through maceration. 

Serve at room temperature or just slightly chilled, with a sprig of mint for color if you like.