Hi Giana,
The first thing would be to find a cookbook agent. To do this, you put together a book proposal with a table of contents and a couple of sample chapters and at least 10-15 recipes. Then you send this around to agents who represent authors with similar works. There are online tutorials on putting together a book proposal, and you can look in the Acknowledgments sections of similar books to find agents. (They are always thanked by name!) Nowadays a social media following is essential for successfully pitching cookbooks.
Good luck!
------------------------------
Califia Rozell
Sacramento CA
------------------------------