Using a sharp knife, cut a cross in the base of each tomato, except for any cherry tomatoes. Working in batches, blanch the tomatoes in boiling water for 30 seconds, until their skins loosen. Drain the tomatoes and leave until cool enough to handle, then peel the skins away from the cross. Cut each tomato into quarters and remove the core.
Arrange the fresh herbs in a slow cooker. Scatt