For much of its history, Chipotle Mexican Grill (NYSE: CMG) bucked the traditional fast food psychology around menu additions. While its rivals tend to rotate items on their menus with limited time offers, Chipotle stuck to the basics. It offered four types of meat (barbacoa, steak, chicken, and carnitas), available in burritos, bowls, tacos, or salads, with customizable toppings.