Pork Tenderloin with Celeriac Creme and Puy Lentils

Bonjour! I've been fancying it up lately - in my own mind, anyway - and decided that what's missing in my relationship is extra un-necessary work. I've decided to try and do a Sunday lunch for the boyfriend and me at least a couple times a month.
I'm using the back section of I Know How To Cook by Ginette Mathiot (one of the giant Phaidon volumes), the bit where famous professional chefs give meal ideas.
I quite hate celeriac, and it features in this dish quite prominently, but actually boiled in cream and mixed with lentils, the flavour is very subtle. We both agreed, and so much so that I was prompted, for the first time, to defile a cookbook and leave a note for my grandchildren.
The recipe was to serve 4, but somehow there didn't seem to be any leftovers, don't know wht happened there...