All I did with one of mine was offer it. She has a voracious feeding response, and would eat every other day if I let her.

The other one took a lot of work. I finally have her eating rat pups by scenting them with mice bedding I got at the pet store, and jiggling them by the tail a bit in a pair of tongs in front of her hide entrance. (I feed F/T only)

Keep a bag a frozen rats in a large pizza rolls box. Works like a charm. If your BF can't stand having bagged frozen meat in his freezer tell him to sack up a bit