I asked Charm what it was and she said it was pretty much ground nuts and sugar. Why it was pink I'm not sure, but these little pink rocks form the basis of the filling of another specialty food of Lyon, the tarte aux pralines. Although my sister helped her host family make one during her stay in Lyon, she had forgotten how to make it so I stumbled through the French instructions attached to the packet with my year 10-standard knowledge of the French language.
It ended up being simple enough though - I just had to make my sweet shortcrust pastry, dissolve the pralines in some cream and pour it into the baked pastry and let it set in the fridge. When I added the pralines to the cream and it started dissolving it turned a bright red colour and here is the finished result:
It was rather lurid and to be honest the striking red colour was a bit off-putting at first. But I cut myself a slice and tasted it.