Chop the chocolate into small pieces and put in a bowl set over a saucepan of barely simmering water.
Allow the chocolate to gradually melt, taking the bowl off the heat once it does. Stir gently until completely smooth and set aside.
Drain a 400g tin of low-sodium chickpeas into a large bowl and reserve the chickpeas to use in another recipe.
Stir the cream of tartar into the aquafaba, until dissolved.
Use a hand or stand mixer to whisk the aquafaba, initially on low speed and increasing to maximum speed once it starts to gain volume.
Add the maple syrup and continue to whisk until the aquafaba meringue forms firm peaks. This can take several minutes.
Add a few spoonfuls of the aquafaba meringue into the melted chocolate and use a balloon whisk to mix together.
Gradually add the remaining aquafaba meringue to the chocolate and mix together gently until the mousse is completely smooth.
Divide the mousse between four small jars or glasses.
Top with fresh berries, garnish with edible flowers and serve immediately.