Chipotle's business can still double in size in the coming years.Everything was going well for Chipotle Mexican Grill (CMG 0.90%). The company grew at a decent pace, profits were strong, and its stock price had more than tripled in the last five years.Just when investors were expecting the restaurant to keep up with its strong trajectory, CEO Brian Niccol announced his departure to join Starbucks. Niccol has been instrumental to Chipotle's outperformance since he joined in 2018, so investors were concerned ...