Move over, Shake Shack. Danny Meyer is adding a lot more green to his menu.

In a rare move for Shake Shack founder Danny Meyer, his company Union Square Hospitality Group announced Wednesday a minority investment in California-based restaurant chain, Tender Greens. This is the first outside investment for USHG, which started a dozen New York food establishments--including the now-public Shake Shack and three new restaurants that just opened this year.

Tender Greens falls under the fast casual category, however the 22 locations aim for top-notch food with a personal touch. An experienced executive chef with autonomy to offer seasonal specials, featuring straight-from-the-farm ingredients runs each kitchen. But the front-of-house is relaxed--customers line up at the counter to order a protein however they like it--in a sandwich, on a salad, or with sides.

“We just happen to have taken the waiters and white tablecloths out of the equation and made it a more accessible experience,” Erik Oberholtzer, of three founders, told Dealbook.

Meyer, who will join the company’s board of directors, agreed Tender Greens had something special--an idea he wishes he’d thought up. Though USHG has never invested in an outside business before, Meyer said in a press release there were no restrictions on helping grow a company with a great idea and shared values. 

“Up until now, we’ve built our company by planting seeds from scratch, and then growing them ourselves,” says Meyers, “Lately I’ve been asking, ‘Whoever wrote the rule…’”