Berry tartlets are a wonderful, simple way to use fresh fruit. We found these little beauties on Little Upside Down Cake (well worth a peek - the photography alone was enough to get all our stomachs rumbling).
Follow blogger Sanda's example and make up the pastry cases and creamy mascarpone, then let your picnic-mates assemble their own tartlets, tumbling a mixture of berries and crunchy chopped pistachio on top for a relaxed but delicious end to your meal.