I used to visit Mona quite often several years ago though always at weekends & unless things have changed I only used to phone the Mona flying club for PPR then drop in, pay about a fiver & have a Bacon butty or two..........sadly I hear that the cafe has now closed !
As far as I was aware the RAF run it during weekdays offering fire cover etc.. but at weekends the Mona flying club operate from there as an unlicensed field.
Neg G