Can either of these stocks become the next big restaurant chain and create shareholder value?If you enjoy a good fast-casual meal, you might have already sampled the Mediterranean-style offerings at Cava Group (CAVA)'s restaurants or the healthy-oriented fare at Sweetgreen (SG 1.38%). You might even have a favorite dish, but which of these hot stocks is the better buy?Healthy and growingCava and Sweetgreen operate similar models. Both are small but growing restaurant chains with the fast-casual model and of ...