Hellooo I need suggestions..?

My pekingese pup is not eating his specified royal canin puppy food which is suggested by vet. Sooo now I jus gave him boiled egg without yolk...he loveedddd it. Plz tell me whatelse he would love to eat like only boiled home food. Like boiled egg,boiled chicken....whatelse can I give him? Plzzz tell meee....I'm worried. He is not eating his pup food