Shares of Zoe's Kitchen (NYSE: ZOES) plunged 40% to an all-time low on May 25 after the Mediterranean-inspired restaurant chain missed first quarter expectations and slashed its full-year guidance. Zoe's revenue rose 13% annually to $102.1 million, but that missed estimates by $3.2 million.However, most of that growth was driven by new restaurant openings, since its comparable restaurant sales slid 2.3% -- compared to expectations of 0.5% growth.