Multitask or Unitask?

I am good at multi-tasking, and I do know my limits.
Something that really ticked me off was that my old boss was slow and and uni-tasker but expected me to do three times the work she did (which I could do if I really pushed it). While she took frequent breaks while working on the same thing all day, she would ask how many things I had gotten done that day and would get short with me if I was only doing one thing.
After a while I told her that I felt it was unfair, she tried to stop doing it, but kept doing it when she got behind. Slacker.