what are you feeding? where did you get it, and was it eating before you got it?
tank size and water parameters?
I think the best thing for a persnickety angel is live rock covered with live stuff - sponges, algae, worms. If you don't already have some really nice pieces of cured live rock in the tank, consider getting some.
I have found many angels that won't eat will pig out on frozen mysis. Might soak with garlic first...