Image: Chipotle Mexican Grill.

In the restaurant business, fortunes can change in an instant. Investors in Chipotle Mexican Grill (CMG -1.34%) and Chuy's Holdings (CHUY -1.72%) know that well, and Chipotle's recent foodborne-illness woes have made many investors take notice of other industry players like Chuy's. With Chipotle stock down and out and Chuy's shares climbing, investors want to know which is the better pick. Let's take a look at how Chipotle Mexican Grill and Chuy's Holdings compare on some key metrics to see which deserves your attention right now.

Valuation
Over the past year, Chipotle and Chuy's have moved in opposite directions. Chipotle's stock is down more than 25% since early 2015, but Chuy's has soared 44% over the same timeframe.

Despite the disparate share-price performance between the two restaurant chains, simple valuation methods point to a lot of similarities between Chuy's and Chipotle. As high-growth stock prospects, both carry relatively high earnings multiples, and even after its share-price plunge, Chipotle stock trades at 35 times trailing earnings. That's only a slight discount to Chuy's and its 38 trailing earnings multiple.

Moreover, when you look at forward earnings, the situation reverses itself. Chuy's weighs in with a forward earnings multiple of 33, which is less than Chipotle's reading of 36. Based solely on this reading of valuation, Chipotle and Chuy's look very similar.

Expansion
One key to understanding restaurant companies is seeing the pace of their expansion efforts. In recent years, both Chuy's and Chipotle have dramatically increased store counts and widened their reach over their respective coverage areas.

For Chuy's, the young company's network of locations is still modest but has grown quickly. As of the end of 2015, Chuy's had 70 restaurants in 14 states, having opened 10 new locations in just the past year. Since the end of 2012, Chuy's has boosted its restaurant counts by 75%, and plans for 2016 include 11 to 13 more locations to open before year-end.

Chipotle's fast-casual chain has a much more extensive reach, and its pace of growth has been impressive. During 2015, Chipotle opened 229 new restaurants, bringing its total count to 2,010. Chipotle expects another 220 to 235 locations to open during 2016, and the pace of its expansion has really picked up since the end of 2013, when the company had 1,637 restaurants under its corporate umbrella.

In terms of percentage growth, Chuy's has the upper hand on the pace of its expansion. However, when it comes to sheer mass, Chuy's doesn't stand a chance against Chipotle.

Financial growth
Currently, Chuy's and Chipotle are in much different situations. Chuy's has seen expansion-driven growth take firm hold of its financials, and its most recent results included a 15% rise in revenue and a 29% jump in adjusted net income. Comparable-restaurant sales growth of 3.2% came from a rise in average check size, and smart cost controls have taken advantage of favorable markets for food ingredients to reduce overall expenses. Chuy's set expectations for 8% to 13% growth in earnings for 2016, and the extent of its new locations will keep revenue climbing as well.

Chipotle, on the other hand, is dealing with the aftermath of its foodborne-illness incidents. In its most recent quarter, revenue dropped nearly 7% on a 14.6% plunge in comparable-restaurant sales, and that sent net income down by 44%. The company also predicted that 2016 would remain tough, especially in light of criminal investigations from the federal government into Chipotle's food safety practices. Chipotle is committed to putting the incidents behind it by "layering on our rigorous food safety program," co-CEO Monty Moran said in its earnings release in January. Nevertheless, investors expect that earnings will stay flat for at least a year before recovering.

For now, Chuy's seems to have the inside track to growth without any of the complications that Chipotle is going through right now. In the long run, though, Chipotle is aiming to become a much larger player in the restaurant business than Chuy's will likely ever attain. Long-term investors can decide for themselves whether they want the immediate gratification that Chuy's can provide or the higher potential from Chipotle.