Put the water, honey, sugar and cocoa powder in a saucepan and heat on a low flame, stirring occasionally, until the sugar has dissolved.
Take the saucepan off the fire, add the chocolate pieces and stir until the pieces have melted. Let cool down.
Pour the mixture into an ice cream maker and leave to freeze with the engine running (or freeze in the freezer) until ice crystals form. Remove and stir until smooth, then freeze again.
Repeat the process again and let it freeze completely.
Take the sorbet out of the freezer approx. 10 minutes before consumption, portion it and serve with the red berries.