Courtesy: Chipotle

If you could watch a time-lapse video of the happenings inside of a Chipotle Mexican Grill (NYSE:CMG) over the past few years, you would see a lot of customers and burritos moving in and out, (with traffic getting especially heavy in the most recent few months) but what you wouldn't see much of is change to the restaurant's menu. That's because the company doesn't need to change its menu. Instead, the company focuses on the quality of its ingredients, and customers are willing to keep paying more for that. 

Chipotle has been a Wall Street darling for a few years now, with exceptional growth and proven customer and market satisfaction. The brains of the operation, Steve Ells, has been adamant that the food sold to consumers would not be compromised for short-term profits or cheap gimmicks, a different mind-set than management at McDonald's (NYSE:MCD). It seems that this plan has been working well for Chipotle, and the stock is up over 770% in the last five years.

The Chipotle menu, just like it has always been
Year after year, Chipotle's menu stays pretty much the same with few additions to the line-up. The main idea, the burrito that customers can customize during their order with different meats, salsas, and wrapped in a tortilla or made "naked" in a bowl, has kept customers coming back since 1993. The few additions to the menu that have been introduced, things like tacos and quesadillas, still fall within the same basic ingredients, just with different shapes.

Courtesy: Chipotle

Other companies, like McDonald's, have lots of new options available often, putting out new menu items for different seasons or when the company needs a new marketing release. While these new items give the company a reason to put out more promotional tools, few stick around to make much of a splash affecting the company long term. Still the company continues to change its menu frequently to try and bring in customers with new items.

It's all about the ingredients
Instead of creating new menu items and using those new products for marketing purposes, Chipotle uses its base of quality ingredients as its marketing message. The company strives to constantly upgrade the sources of its ingredients, such as using locally sourced food from family farmers, serving organic meats raised without antibiotics, and using the freshest veggies possible with little or no additives. This has been the case since the company started its "food with integrity" campaign a decade ago.

Food With Integrity is Chipotle's commitment to changing traditional "fast food" culture by serving customers the very best ingredients, all raised with respect for the animals, the environment and the farmers.
-- Chipotle's Food With Integrity campaign

This plan has gone a long way in letting Chipotle keep one consistent, long-term marketing message, and has been paramount in pleasing customers enough to build a very loyal fan base. Even without a changing menu, customers don't seem to be getting bored with the options, and are even willing to keep paying more and more for these burritos.

One thing that does change: Prices
To keep these ingredient improvements coming, as well as the company's profits moving forward, Chipotle's prices have gone up recently, with as much as a 6% rise in April of this year.  

In the most recent quarter reported, Chipotle's revenue increased more than 28% year over year and same-store sales were up a 17% year over year, leading to net income increasing more than 25% year over year. Chipotle is also on track to reach its goal of opening as many as 195 new stores in 2014. It currently operates more than 1,650 restaurants. With all of these new stores, rising same-store sales, and a proven menu that works, customers are not the only ones who should be happy. 

Chipotle investors are hungry, too
Increased prices don't seem to have changed customers' love of Chipotle's classic menu. Pricing power like this, as well as proven quality and products that please customers without needing constant new product gimmicks to make new sales, are reasons why Chipotle is the kind of company that investors should be happy to own long term. That's great if you bought Chipotle shares five years ago, but is there any upside left now?

With the added stores in 2014, and growing revenues and profits, there are plenty of reasons to think that there is still a lot of upside with this stock. Further, there are no signs Chipotle is moving away from the simple menu approach that has been so successful historically. Even at a P/E of 60, which is expensive in this space compared to a competitor like McDonald's at a P/E of just 17, Chipotle's growth potential looks very strong going forward and five years from now current prices will probably look like a value. So potential investors  might think about wrapping this one into their own portfolio.

Bradley Seth McNew has no position in any stocks mentioned. The Motley Fool recommends Chipotle Mexican Grill. The Motley Fool owns shares of Chipotle Mexican Grill. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.