Celebrity chef and restaurateur Mario Batali told CNBC on Monday he believes Shake Shack (SHAK), which started as a New York City food stand, is "slightly overvalued for 63 restaurants." Batali also said, "Bravo," when asked what he thought about the IPO, which he did not invest in. "I don't have like a really giant portfolio of investments outside our stuff because we reinvest all of our money in projects we're going to own." Shake Shack is an "Americana play" because people have a "soft spot for that nostalgic hamburger or shake," he added. Batali has ownership in renowned restaurants in New York, Los Angeles, Las Vegas, Singapore and Hong Kong. He also helped start the Italian food court and grocery store Eataly, with two locations, one in New York and one in Chicago. The celebrity chef co-hosts ABC's "The Chew," a daily talk show, which focuses on food, lifestyle and entertaining. He also launched last month an online video series on DailyMotion.com called "Feedback Kitchen." The five, 22-minute episodes should have a million views each by the end of this week, he said. "I love music almost as much as I love food," Batali told CNBC, when describing the concept of the Web series. The show features musicians including guitarist "The Edge" of U2, singer-songwriters Josh Groban and Patti Smith, and Red Hot Chili Peppers bassist Flea. "I make them lunch. And then they make a song for me," said Batali, who could see himself generating more "Feedback Kitchen" episodes in the future.