I would take a way different angle. I believe your employer already knows you are due additional compensation and that is why it is getting put off. Maybe they don't have current resources to give you what they deserve so he is kicking the can down the road.

What I would do is walk up to him/her and say "Name, I want you to know that I am really excited about how I have grown and developed here and hope that as part of our next step we can sit down together and plan a long career path so I can continue to be a bigger asset for you. I know your very busy but this is a priority to me, would it be possible to set a firm time/date we can stick to right now?

Don't let the employer stave off having the conversation with you, its a poor leadership tactic and doesn't show respect for the work you have performed or the amount you have grown. I am sure he isn't avoiding conversations with you about other things...