Show featured image next to post-teasers in Genesis Framework?

(Cut/pasted from the OP.)

SOLUTION:

As it turns out, this is very simple.

Go to your Dashboard –> Genesis –> Theme Settings

Now in the box labelled “Content Archives” select “Display Post Excerpts” from the drop down menu. Now make sure the “Include the Featured Image” box is checked and select your image size.

Save Settings.

The featured-image thumbnail will now appear next to your posts.