Chipotle has been executing well lately with sales growth of 14% year over year in the first quarter -- and there's more to come.Chipotle Mexican Grill (CMG 0.21%) is a growth stock with management that is keenly focused on expanding the company's top line. There are two ways for a restaurant chain to do that, and the leadership team is focused on both of them. Here's what you need to watch at Chipotle over the next three years to make sure that the company is living up to its own plans.Chipotle has five go ...