Enigma Sweet Potatoes

These sweet potatoes (served here over CSA arugula and brown rice) were delicious in my lunchbox, but I couldn't quite place the seasoning. The chef was uncooperative when interrogated about the ingredients, though I did get that they were roasted.

Fortunately, Enigma codebreakers, working around the clock, have decrypted the following communique pertaining to Operation: Sweet Potatoes.

... 4 or 5 largish sweet potatoes, half a stick of butter and about that much oil, a teaspoon of liquid smoke, a couple teaspoons of cider vinegar (I think you could double this one -- I couldn't tell if it did anything), cayenne pepper, salt, black pepper to taste ...

It is believed that this intelligence will hasten the replication of the recipe by at least two years.

P.S. The crazies over on the Bitten blog are substituting celeriac for bechamel sauce on lasagna.