Using my Chef Exception & Reporting Handler for Splunk Storm you can easily search for and report on your chef-client runs.
Given you've retrieved your Access Token as ACCESS_TOKEN and Project ID as PROJECT_ID, add a Recipe similar to the example below:
include_recipe 'chef_handler' gem_package('chef-handler-splunkstorm'){action :nothing}.run_action(:install) chef_handler 'Chef::Handler::SplunkStorm' do action :enable arguments ['ACCESS_TOKEN', 'PROJECT_ID'] source File.join(Gem.all_load_paths.grep(/chef-handler-splunkstorm/).first, 'chef', 'handler', 'splunkstorm.rb') end
A search for * should result in events like these:

The following dashboard shows the Average chef-client Elapsed Time by Host:

Here's the assocaited search:
* | spath path=elapsed_time output=elapsed_time | timechart span="15m" avg(elapsed_time) by host