You can use the ini file options and start pyramid just by passing the ini file name.
e.g. bin/pserve development.ini
Gunicorn is loaded in the ini file:
[app:main]
use = egg:myapp
pyramid.reload_templates = false
pyramid.debug_authorization = false
pyramid.debug_notfound = false
pyramid.debug_routematch = false
pyramid.debug_templates = false
pyramid.default_locale_name = en
[server:main]
use = egg:gunicorn#main
host = 0.0.0.0
port = 6543
worker = 4
worker_class = gevent
#worker_class = eventlet
#worker_class = sync