This article is part of our Real-Money Stock Picks series.

Last week, Chipotle Mexican Grill (CMG -1.34%) shares plunged after the company reported quarterly results. Right now, Chipotle may look like it's becoming a "slow food" stock in the fast-food realm, but there are several reasons why true long-term investors shouldn't sweat the short-term.

For whom the Bell tolls
Chipotle's quarter missed analysts' expectations, but the results were actually pretty robust considering America's overall economic situation hasn't been great lately. Double-digit percentage increases in sales and net income certainly don't make me think there's any reason to push the panic button.

Meanwhile, Chipotle's plan to test out its ShopHouse Southeast Asian concept in Los Angeles is a heartening sign for future growth avenues, too. 

Count me in the camp that thinks the David Einhorn-fueled idea floating around that Yum! Brands' (YUM -0.12%) Taco Bell is a threat to Chipotle is outlandish, even if Taco Bell is fancying up its offerings.

Chipotle's Food With Integrity mission is far removed from anything Taco Bell can utilize as an "add-on" to its menu. Chipotle's ahead of the curve in embracing food ethics, which more and more American consumers find appetizing. A company like Whole Foods Market (WFM) couldn't have thrived like it has if more Americans hadn't started to understand the importance of what goes into their bodies and started rejecting the worst elements of factory farming and unsustainable agricultural practices.

Let's also remember that Chipotle has plenty of room to grow, here and overseas. There are 1,350 Chipotle restaurants. If you want to make a comparison, consider that former parent McDonald's (MCD 1.70%) has more than 33,000 restaurants worldwide. For what some would call closer to a burritos-to-burritos comparison, Yum! Brands boasts nearly 6,000 Taco Bell restaurants.

Slow down!
Granted, my play on the term "slow food" to speak about Chipotle isn't quite right. The real slow food movement emphasizes local, sustainably grown, artisanal, seasonal foods, and as USA Today once put it, "everything fast food is not."

However, Chipotle does speak to the movement, since it seeks to incorporate high-quality, organic, local ingredients whenever possible, a real game-changing idea in the fast-food realm.

Chipotle may be a "slow food stock" for a while; one of the things that alarmed investors was Chipotle's prediction of flat to single-digit comps next year. However, I'm wondering if 2013 is going to be rough on many, many companies, and it may test even the most stalwart long-term investors.

Let's be patient, though: One of the worst things about the marketplace in recent decades has been the pressure on corporate managements to deliver growth right now for Wall Street analysts and frenetic traders with the attention spans of sand fleas -- and this outlook has caused many a great company to lose its way. We Foolish investors can -- and should -- fight that tendency.

Profits through patience
I purchased shares of Chipotle twice for the real-money portfolio I'm managing for Fool.com, and although both buys are in the red right now, Chipotle remains one of my favorite long-term choices. I've purchased shares for my personal portfolio, too. Obviously, I believe this is a disruptive, forward-looking company with excellent future growth possibilities.

I've also got my eye on Panera (PNRA), which reports its quarterly results tomorrow. Some temporary weakness in its stock price would make it a tempting addition to the portfolio, and Panera also has interesting social initiatives built into its mission. For example, take its budding Panera Cares community cafes, which feed customers regardless of their ability to pay.

Chipotle shareholders with a truly long-term view have no reason to panic. For those who have been craving the company's shares, consider times like this an opportunity to scarf up bargain-priced shares of a great business.