Recently i needed to troubleshoot some requests to an HTTPS server. Instead of going through the hassle of setting up mitmproxy to middle the SSL connection, I just decided to point to to an empty listening port. After all, all I really needed was to see what GET requests it was making.
You can set up a netcat like server that supports SSL using ncat (the tool that comes with nmap).
ncat --ssl --listen 4443
If you want it to stay open after the first connection, append '--keep-open' to the end. And if you want some verbosity to whats going on, add '-vv' to get more info.
There are supposedly a bunch of different ways to get a netcat like interface for SSL but ncat gave me the least trouble.