One of the first in the wave of mobile vendors in St. Louis, Cha Cha Chow harkens back to the prototypical food truck, focusing on tacos. These aren’t traditional Mexican tacos, mind you; they’re playful takes on the form. The best might be the beef short rib, the meat braised for five hours and served with red cabbage and a creamy, spicy “Cha Cha Sauce.” Other taco varieties include pulled pork with salsa verde, and curried sweet potato. A few sandwiches, including a good grilled burger, are available. The homemade aguas frescas present a refreshing alternative in the beverage department.