I think you have to hack by yourself a theme. The home.php or maybe the index.php file of the theme is involved. Have a look at your own theme, and have also a look at some theme that puts on the frontpage both the content of the “about” page and some recent posts. Several themes do it; for instance “Hemingway reloaded”. Of course, such a theme often only puts the excerpt of the “about” page rather than the whole content, but this is not difficult to change.