Add "search bar" in the main menu

I have installed joomla 3.4, with the "Steak House" template.
My problem is that I want to put in the main menu, a bar of search (or as close as possible). If you look at the attached picture you see what I would like to have.



My URL is: http://www.unicadem.com

Appreciate detail in the explanation. Thank you very much for his trouble.

Hi,
it request customization,
and via support we can give you only basic tips,
it means that you have to it "alone".

1) Edit: template\gk_steakhouse\layouts\default.php
2) Inside find <div id="gkMainMenuRight"> .... </div> - there you have to add new module position
3) Inside gk_steakhouse\templateDetails.xml add new module position name
4) Publish search module in new position and using CSS try to fix it appearance

I do not know how to do it. Anyway thanks for trying to help.