One thing I do for my shy bichirs (my Palmas palmas especially) is to feed after the light turn off, and leave extra fish pieces (silverside, smelt, tilapia ... etc) sitting around overnight. With all the lights out (only "moon" lights in the tank), I've seen the palmas eat. Normally, I just leave the food overnight. In fact, I've had left over food the next morning (in my tank, the lights turn off at midnight, food dropped into tank at 2 am), but it's always gone by the time I get back from work in the evening.
BTW, because I leave food sitting around for so long, I have a huge biological filter (a 26 gallon flat bottom tank filled with bioballs, with pump from my sump to it, and overflow back).