Open chicken tortes with mediterranean bagna cauda

I first tasted a dish similar to this while in the South of France on a mystery stop eating tour. I loved the flavours: they were redolent of that entire part of France. Once I was home, I just had to recreate the experience. Here I make four individual tarts but if you prefer, you could make one large one in a big cake tin. I like to serve this with a fennel purée.