The less you like talking on the phone the more phone calls you should make. Assuming you are polite.
Unless the time of the call was pre-arranged the person placing the call is always going to have more time to talk than the person receiving the call simply because the caller is the one making the call. So if you receive a call but you are too polite to make an excuse to hang up you are going to be stuck talking for a while.
So in order to avoid talking on the phone you should always be the one making the call. Try to time it carefully. It shouldn’t be at a time when your friend is completely unavailable to take your call because then you will have to leave a voicemail and he will eventually call you back when he has plenty of time to have a nice long conversation.
Ideally you want to catch your friend when they are just flexible enough to answer the phone but too busy to talk for very long. That way you meet your weekly quota of phone calls at minimum cost in terms of time actually spent on the phone. What could be more polite?