Place the blackberries and all the other ingredients up to and including the thyme in a pan, bring to the boil while stirring, cover and reduce for approx. 30 mins. over a medium heat, stirring occasionally.
Fill the prepared jars with the mixture, seal immediately and leave to cool on a cloth.
Place the Tommes on a baking tray lined with baking paper, season with salt, sprinkle with thyme. Bake for approx. 7 mins. in the centre of an oven preheated to 180°C.
Spoon the chutney on top of the cheese, season.