gistfile1.txt

http {

 ...

  #local chef server
  upstream chef_api_local {
		server localhost:4000;
  }
  #local chef webui
  upstream chef_webui_local {
		server localhost:4040;
  }

  ...
}

server {
	server_name yourchefserver.gymsock.org;
	ssl on;
	ssl_certificate /etc/ssl/gymsock.crt; 
	ssl_certificate_key /etc/ssl/gymsock.key;  	
	listen 443;
	
	root /var/www;
	
	location / {
		#API request incoming
		if ( $http_x_ops_timestamp != "" ){
			proxy_pass http://chef_api_local;
			break;
		}
		#webui request incoming
		proxy_pass http://chef_webui_local;
	}
}

Thanks to Jonathan and Miguel for the inspiration: http://jpluscplusm.com/blog/2010/07/06/hosting-a-chef-webui-and-api-behind-the-same-ip-port-and-ssl-certificate/

Just a issue i found: I got errors when uploading a cookbook using this... Had to add: proxy_set_header X-Forwarded-Proto $scheme; to make this work