Celeriac Purée with tapenade

This is so straightforward, it isn't even worth writing out as a recipe. Simply peel and cut up the celeriac, then cook in salted water until tender, exactly as you would for potatoes. Drain, and puree in the food processor. A few minutes before you're ready to serve it, re-heat gently in a saucepan in which you've melted a generous amount of butter (about an oz per serving) and thoroughly mix in a heaped teaspoon of tapenade. That's it. The tapenade gives an edge and some complexity which the celeriac otherwise lacks - I find celeriac purée tends to be delicious at first bite, but by the third mouthful, it's definitely getting a bit 'samey'.  
We had this last night along with a simple dish of grilled lamb cutlets, but it would go well with practically any roast, or could form an interesting base for croquettes (mixed with cheese or minced chicken, for example.)

Tonight's dinner:

Artichoke 'Fonds' stuffed with pork and parmesan.

Fiorentina, with parmesan and rocket.

Baked lemon cream, with blackberries.