I have not tried that before, but it seems possible. You can have a single restaurant and replace the home page with a menu page. The Enter your Address and Go button on the home page is rendered by the Local Module, so uninstalling/deactivating this module will do.
However to make the user go straight to menu instead of the homepage, go to system/tastyigniter/config/routes.php and change line 9
$default_controller = 'home';
to
$default_controller = 'menus';
.
What that does is change your default homepage to menus page.
BTW, you may loose all changes when upgrading in future
Sure let me know what other issues you come across as this hasn't been tested and at some point i thought of adding the option to enable/disable the location search but wasn't feasible.