Ex-'RHOC' Star Gretchen Rossi Sued By Her Own Lawyers

Gretchen Rossi may have to lawyer up somewhere else after she stiffed a law firm for hundreds of thousands of dollars ... according to a new lawsuit.

Brown & Charbonneau, LLP -- a SoCal business and family firm -- just filed suit against the ex-'Real Housewives of Orange County' star, claiming she left 'em hanging with an invoice of about $285,000 in late 2013 ... and then another for $16,000 a few months later.

Gretchen's camp tells us she hired B&C to work on a harassment case and plans to pay her unpaid balance once she collects in an unrelated legal matter. She chalks it up to a "misunderstanding."